paddler question

billyboy
27th October 2005, 12:59
can anyone tell me if there was ever a paddler built that had the capabilityof going ahead on one and astern on the other for manouvering? I think not, but my overeducated mate here says there was. anyone help on this one? I got a large tot staked on this one guy's

Piero43
27th October 2005, 14:39
I'm not a paddler expert, but, technically speaking, the only way would be to operate the port and starbord wheels with two indipendent engines.
Another way could be to insert two reverse gears between a single engine and the two wheels, but this looks quite intricate and scarcely reliable in manoeuvering, expecially in emergency.
So: has ever been built a paddler with two indipendent engines? The answer to our historical experts!
P.

Bruce Carson
27th October 2005, 15:09
Hi:
There were a few.
I posted a picture in the Gallery of the train ferry 'Solano' on Oct. 2.
She had independent walking beam engines on the centerline, each attached to separate paddle shafts.
The following site has photos of a model of the ferry showing the configuration of the engines and shafts.
http://www.cprr.org/Museum/Ephemera/Solano_Ferry_Model.html

Bruce C.

Derek Roger
27th October 2005, 15:31
To my knowlege independent drives to each paddle was the norm. As such they were very easy to manouver.
For efficiency the paddle blades "feathered " to maintain a vertical position relative to the water ;that is; they did not lift water on the blades upward portion of the revolution .All the effort being put into forward motion or astern as the case may be.

Valayer
27th October 2005, 15:45
Believe the Tay paddler-ferries, before the war, and until early 50's (BL Nairn and Sir William High) had a pair of horizontal steam engines, one port one starboard. I used to watch them as a kid from the lounge, which had windows overlooking the machinery.

Bruce Carson
27th October 2005, 20:01
I remember reading somewhere that most British paddlers did not have independent shafts, but paddle tugs, as a necessity of their business, did.

Bruce C.

neil maclachlan
28th October 2005, 02:25
Hi Guys,
Re the paddler question, I served my apprenticeship with a company famous for building steam engines,by the name of "Rankin & Blackmore Ltd"Eagle Foundry, Greenock Scotland. During my time there we built a number of side paddle and stern wheel engines. The side paddlers were the "Waverley, Maid of the loch, Bristol Queen" None of these ships had paddles independantly driven as the crankshaft drove both paddles,the paddles had a eccentric feathering device that allowed the paddles to feather as they came out of the water. I sailed on many paddle steamers during my younger days on the Clyde and never once saw any steamer of that type different,the only one different from the normal was the "PS Talisman",she had a diesel engine by British Polar Engines Ltd of Glasgow driving an E.E.C. Electric Motor. The Talisman was built by A&J. Inglis of Pointhouse on the Clyde same builder who built "Waverley". My grandfather was a tugboat master with Clyde Shipping Company, he was master of the "Flying Scotsman", she was a paddler and had a beam engine both paddles driven by the one engine. Hope my comments may help clear up the question although I feel there may be an arguement somewhere?
Awra Best--NeilMac.

Derek Roger
28th October 2005, 02:51
An interesting subject . Both Valayer and I have the same recollection of the BL Nairn having two horizontal steam engines . It is most unlikley they were connected however I keep an open mind. Some more research is necessary . Back to the old textbooks ! However from what you tell us Neil it seems it was not the norm to have independant paddles .
Cheers Derek

Bruce Carson
28th October 2005, 02:53
Both survivng British built paddle tugs that I know of, the 'John H. Amos' and the 'Eppleton Hall' each have two engines turning independent shafts.

Bruce C.

billyboy
28th October 2005, 23:44
Gentlemen, I thank you for the information you have given, looks like i get a free tot!!I also heard the rumor that independant paddles would cause a capsize.

Derek Roger
29th October 2005, 00:51
I have found a number of vessels which have two engines ; each one independantly driving one (1) paddle .

Bruce Carsons comment supports this .

It seems that from about 1850 twin engines each on a separate paddle was the norm for large vessels .

Wee paddlers would not have enough room for a twin engine arrangement therfore would never be candidates for such a drive system .

The disadvantage of independant drives was nothing to do with stability ; but the extra difficulty steering if the two power plants were not giving equal revs /power to the paddles.

A further Big advantage to these configurations as well as manouverability was that there was no crankshaft going across the vessel which opened up the midship space from engine room to cargo or passengers .

A paddle ship going full ahead Port and Full Ahead Stbd would turn on its own axis . Nothing to do with stability which is a function of the GM . It would spin like a top ! ( albeit a slow top )

Most paddle steamers in the UK and Astralia were shallow draft ; flat bottomed vessels ( suited to shallow water operation ) They would have a high GM and if anything would be a bit " stiff '.

Deep sea vessels would be somewhat different and if a passenger ship; it could be a bit "tender " .

This was a function of the design by the naval architects and would not be a result of independant drives to paddles . A transatlantic voyage would not involve much manouvering .

Keep the pot boiling Billy !
You have a hot! one here .


Regards Derek

billyboy
29th October 2005, 11:10
Thanks Roger for that info. Looks like the probability of my free (double) Tot is wavering a bitmate!! coming from Scotish stock this could have a serious effect on "ma weee Sporran" LOL

billyboy
29th October 2005, 12:45
Ah! just a wee minute now. think I can recall as a child hearing that either the "bristol or Cardif Queen" had this capability but were afraid to use iti n fear of stability probs, hence my late father used to swing them round with a TID tug when they were in newhaven for a summer season. gOLLY GOSH , I MUST BE HAVING ONE OF "THOSE" MOMENTS WE CAN SPEAK ABOUT HERE ... lol

Bruce Carson
29th October 2005, 13:40
I had forgotten the most obvious--the "Mississippi" type steamboat on the Western rivers of North America.
The sidewheelers, which outnumberd the sternwheelers by far, traditionally had two single cylinder simple horizontal engines, one to port and the other to starboard independently working the wheels
The sternwheelers often had port and starboard engines to work the single wheel.

Bruce C.

Keith Adams
23rd December 2006, 04:06
A wee bit late with this but Lamey Towing Company on the Mersey had a
paddle tug still operating in the late 1940s... I used to watch her in action in
and out of Alfred Locks in Birkenhead, towing Trampships... in tandem with a conventional steam tug also of Lamey... wish I had taken photos, she could turn
on sixpence! Snowy.

Paedrig
23rd December 2006, 12:33
I believe there were one or two early paddle tugs on the Thames that manoeuvred by virtue of moving a weighted bogie athwartships dipping or lifting the paddles. I was told that they had had a special name..probably unprintable!

billyboy
23rd December 2006, 13:05
Paedrig!! "probably unprintable" you say! ... heh heh heh that should keep a few guessing over the holiday mate ... LOL

benjidog
23rd December 2006, 16:16
Out of interest I just checked out the book "A history of Marine Engineering" but John Guthrie and could find no mention of paddlers with separate engines attached to each paddle. The book seems pretty comprehensive on matters related to engines but obviously he could have just decided not to include such vessels.

Brian

Santos
23rd December 2006, 16:22
Dont know if anyone has seen the following site, very interesting :-http://www.addis-welt.de/smilie/smilie/trinken/37.gif

http://www.megoran.fsworld.co.uk/Independent%20Wheels.htm

Sorry Billyboy, hope your sporran recovers.

Happy Christmas http://www.addis-welt.de/smilie/smilie/trinken/555.gif

Derek Roger
24th December 2006, 01:41
Thanks Santos !
I rest my case !
I was particularily happy to see the comment re the B.L Nairn ( Dundee to Newport ) which both Valayer and I commented on and observed as kids . The Grey Cells are still in good nick it would appear.

Sorry about the Dram Billy ! No mateer I will stand my hand should we meet up some day .
Derek

Alistair Black
25th December 2006, 02:46
Ah! just a wee minute now. think I can recall as a child hearing that either the "bristol or Cardif Queen" had this capability but were afraid to use iti n fear of stability probs, hence my late father used to swing them round with a TID tug when they were in newhaven for a summer season. gOLLY GOSH , I MUST BE HAVING ONE OF "THOSE" MOMENTS WE CAN SPEAK ABOUT HERE ... lol


Given that Bristol Queen was engined by Rankin & Blackmore of Greenock (almost identical to Waverley's engine) and Cardiff Queen was built (and presumably engined) by Fairfield's of Govan, it is likely that both were triple expansion single shafted engines (certainly the case for BQ, would need to research CQ).

The urban myth about passenger paddlers putting one ahead and one astern still rears its misinformed head aboard Waverley despite the obvious fact that there is one continuous crankshaft running across the ship from side to side!

Al.

Tony Breach
25th December 2006, 10:39
Confirm CARDIFF QUEEN was engined by Fairfields,triple expansion.

Books to read:
Paddle Steamer Machinery - a layman's guide. R.J.Ramsay.
Steam at Sea. Denis Griffiths (Chapter 2 - paddle engines)
Neither discuss divided drives.

In correspondence of the magazine Model Boats about 40 years ago concerning the steering qualities of paddlers, there was a letter from someone who I beleive was a senior marine engineer, possibly a surveyor or examiner. He advised that a paddler with divided drive had capsized on the London River with heavy loss of life as a result of turning short round with one engine ahead & the other astern. I beleive this occurred during the latter half of the 19th century; possibly the 1870s. Following the enquiry the use of independently operating paddles was prohibited by the BOT. Does anyone know of this incident? While I fully agree that statical stability is quantified as GM, we are talking about an unusual dynamic condition which may affect the stability and exert a force that will act adversely: is there a naval architect out there who could advise? My own experience of paddle steamers (BRISTOL QUEEN) makes me think that they were a little short of GM but I was an AB on her & not privy to the stability data: perhaps John Megoran could expand on this???

Tony.

billyboy
25th December 2006, 10:45
Dont know if anyone has seen the following site, very interesting :-http://www.addis-welt.de/smilie/smilie/trinken/37.gif

http://www.megoran.fsworld.co.uk/Independent%20Wheels.htm

Sorry Billyboy, hope your sporran recovers.

Happy Christmas http://www.addis-welt.de/smilie/smilie/trinken/555.gif

I thank you for the information and the website evidence. I am away to get the key of my sporan now. sad on the finances but grand on the educationa side .
tank you all for your help guys.
have a good 2007 lads. (Jester)

terence
25th December 2006, 23:44
hey billy boy what about the savannah sailing ship collapsible paddle.wheels
an engine that ran for85 hours that should be onley sorry across the atlantic for 85 days rest was sail terry music man

stein
27th December 2006, 06:15
Quoting from "The Marine Steam Engine" eleventh ed. London 1911: In paddle-wheel tug-boats, gear is usually fitted to enable the wheels to be disconnected from each other, and each engine worked independently, to facilitate the manoeuvering of the vessel. In many cases an ordinary disconnecting clutch is fitted on the intermediate shaft for this purpose.
Another plan consists in fitting a cast iron disc on the intermediate shaft, in lieu of a crank-arm. This is driven by feathers on the shaft, over which it may be drawn back, clear from the crank-pin, when the engines are required to work independently.
In the more recent paddle-wheel tug-boats in His Majesty's service a pair of cylinders, forming a compound engine, has been attached to each crank. The shafts for each wheel may either be connected by a clutch coupling, or left quite independent of each other, for the engines will be entirely under control whether they are coupled or not. (End of quote)
Taking paddle-wheel history as a whole, independently worked wheels are a rarity. The early wooden paddle-tugs with one cylinder single engines did of course not have it. Keeping both wheels on one crank/axle would be an obvious necessity (more so the further from sheltered waters; the in-line engines of Bruce's train ferry is not a workable proposition elsewhere), and workable disconnecting gear with the hammered iron smith-work of the early engines is hard to imagine. Although it certainly must have engaged nautical engineers dealing with tugs and ferries long before it became a reality. An interesting thread that could be long amended; when was it first accomplished? Stein

Chillytoes
4th January 2007, 11:39
Seems that Billyboy's original question has been fully answered 12 months ago, but if I can poke my oar in - "Famous Paddle Steamers" by F.C. Hambleton, published in 1948 notes a London tug, "Aid'. He says - "The 'Aid' was a handy tug, for the port and starboard sets of engines could be disconnected from each other, and she was given a bow-shaped stern and a rudder at both the bow and stern."
My understanding of paddler's manoeuvring is limited but I always thought that some vessels had sliding dog clutches on the paddle shaft so that one side could be disengaged, so improving her handling.
The story of the danger of capsize to a paddler with independent wheels is an urban myth. The fact that such an arrangement was not rare should put that tale to bed. I guess its origin might have been something along the lines of if one paddle was going ahead it would tend to either pull down the nose or pull the hull to that side and the other paddle going astern would therefore lift that side and thus the whole lot would go base over apex. But if this were true, then with both paddles going ahead, the nose would be pulled down and if going astern, the stern would be pushed under. Clearly this does not happen to the extent of causing a problem.
Anyway, hope you enjoyed the drinkies, Billyboy! (Silly question!)

ARTHURHARVEY
15th January 2007, 20:02
The Farringford which originally operated the Lymington/Yarmouth I of W service had independent paddles (twin engines) to enable her to navigate the river but most pasenger paddlers were restricted and not able to operate the paddles independently.Years ago they had a paddler called the Freshwater which again had non independent paddles and to assist navigating the river she a had foresail which was hoisted to pay off the head.When the naval dockyards had paddle tugs these were independent for manoeuvring.The Farringford finished her days operating on the Humber.Yes there was a feathering device on the paddle wheels.

jimmys
15th January 2007, 22:17
Having been for a long number of years the MCA Engineer and Ship Surveyor for the PS Waverley, I deny any knowledge of paddlers. The feathering centre is " The Jenny Nettle" and the drive rod is the radius rod. There has been all configurations as the books will show.
The triple expansion Rankine and Blackmore, vacuum condensing engine is a marvel of engineering. It is fitted in the Waverley in its originality. It is difficult to successfully repair in this day and age and it is a tribute to Waverley Steam Navigation they have been successful.
Every engineer should stand beside it and look in wonder.

best regards
jimmys

RayJordandpo
15th January 2007, 22:38
United Towing had a paddle tug called 'Frenchman'. It was built by Earles of Hull in 1892 and manoeuvered with independant paddles. During the summer it would operate out of Bridlington as a pleasure steamer. I remember it as a coal hulk in the River Hull (Old Harbour) when I was a kid. There is an excellent photograph of her in Brian Fisher's photo collection online.
Ray Jordan

billyboy
17th January 2007, 05:20
Very good gentlemen, some very interesting comments and information.
Now, heres another challenge for you all. does anyone know what the strongest recorded bollard pull by a paddler tug was? I would be very interested to know just how hard they could pull with paddles. I think it would be higher than most of realise.

K urgess
17th January 2007, 10:19
Didn't the RN stage a competition (tug of war) between a paddler and a screw driven vessel to determine which type was strongest?(?HUH)

The report may give some clue as to bollard pulls.

RayJordandpo
19th January 2007, 01:43
Didn't the RN stage a competition (tug of war) between a paddler and a screw driven vessel to determine which type was strongest?(?HUH)

The report may give some clue as to bollard pulls.

According to an article online, in 1848 the British Admiralty held a tug of war contest between the prop driven ship 'Rattler' and the paddle driven vessel 'Alecto'. The 'Rattler' won towing the 'Alecto' astern at 2.8 knots.
Ray Jordan

jimmys
19th January 2007, 20:14
The competition screw/paddle was a foregone conclusion. The screw was in the water constantly and the paddler's floats entered and left the water. During this entering and leaving the paddlers efficiency precluded it winning the competition.
The support was there for the paddler as it looked better, thrashing away. There was very little to see at the screw and that is the reason for these big notices at bow thrusters.

best regards
jimmys

K urgess
20th January 2007, 18:09
Regarding Billyboy's question about bollard pull.

The only thing I've found so far is the attached table from "The Screw Propeller" by A.E.Seaton published in 1909.

Headed "Examples of paddle wheel steamers having side wheels with feathering floats." it has a column "Tow Rope H.P." which may give some indication to those engineers amongst us who understand such things.

I am, sorry, I was, just a humble sparkie so such matters whistle past over my head at 37,000feet doing mach 2!(==D)

Of further interest is the opening page of this chapter on paddle wheels, bearing in mind that this was published 98 years ago.

"PADDLE WHEELS
The paddle wheel as a marine propeller is still in use, and as it has certain qualities of its own which cause it to be valuable under certain circumstances, it is likely to continue in favour in spite of other characteristics which are against it when compared with the screw.
To-day it is employed on certain services such as --
(a) Tug-Boats. - Where quick manoeuvring is absolutely necessary it can be accomplished by disconnecting the wheels and working them independently, so that while one is moving "ahead" the other may stand still or move "astern," the turning moment being then greater than that of a twin-screw boat of equal power. Paddle wheels also have a more positive action, so that motion is imparted to the ship and retardation produced when required much quicker than with screws."

It goes on to mention river steamers, steamers in tropical shallow waters and steamers making calls at piers and wharves as being vessels that benefit from the use of paddle wheels.

It also notes that "when damaged the former (paddle) can be examined and repaired, without taking the ship out of water, by an ordinary mechanic such as a country blacksmith".

The whole subject is fascinating and if anyne wants more details about paddles I'll gladly scan the piccies and transcribe the text for your delight.[=P]

Derek Roger
20th January 2007, 19:41
Would to see some more pics /details Sparks . Derek

billyboy
21st January 2007, 13:04
getting more interesting by the minute gentlemen.
My personal view is that it would depend on the diameter of the paddle wheels and the length of the floats used. I still think it could be surprising just how much bollard pull a paddle wheeler could exert given the right circumstances.
They didnt sem to have much problems shifting the warships around in places like Portsmouth and plymouth. be fascinating to find out.

billyboy
21st January 2007, 13:07
thanks for posting the table Marconi Sahib. some interesting details there mate

K urgess
21st January 2007, 14:05
Derek & Billyboy - now you've done it. It doesn't take much encouragement to get me started.(Smoke)
I'll post some more as soon as I can. The design of paddle wheels is not just some bits of wood angled on a big wheel.

First I shall have to figure out how to write equations so they make sense when posted.[=P]

If you look it seems that the size of the paddle has some bearing on the tow HP.

BarryM
21st January 2007, 14:17
Search 'Model Ships>Model Paddlers' on this forum and you'll find that independent/fixed paddle drive has already been discussed. Few British sidewheelers were built with independent wheels because of their effect on stability as one wheel could be driving water while the other could be turning in air if going in different directions in any sort of sea. Exceptions were the (six??) diesel-electric tugs of the RN 'Director Class' which were built in the 50's with independent paddle control to assist in manoeuvering aircraft carriers. Do we have any surviving crews of these vessels who could comment on their performance?

K urgess
22nd January 2007, 00:27
To continue where I left off quoting from "The Screw Propeller" by A. E. Seaton.

"(b) In river steamers, when draught of water is very light, there is not the same limit to the size of propeller with the paddle as with the screw; and although this is not so marked a difference as formerly, owing to Sir John Thornycroft's and Mr Yarrow's inventions, whereby partially submerged screws can be worked with a high efficiency, it remains and is only a matter of degree. The fact is that in very shallow water the paddle wheel only can be employed with advantage.
(c) Steamers in tropical shallow waters, where weed grows rapidly and frequently forms a serious obstruction to navigation, are better fitted with paddle wheels, as they can be cleared when clogged much more easily and quickly than screws can be. Moreover, in practice, screw boats have a greater tendency to "suck" the bottom and be retarded by nearness to the bottom than paddle boats.
(d) Steamers making calls at piers and wharves which have the side paddle wheel are much more manageable and handy than twin screws, and, even in fine weather, lose less time at each stopping-place consequent on having the same qualities as a tug-boat; besides which the sponsons or platforms ahead and astern of the paddle boxes permit the placing and using of mooring bollards and posts, for the spring by which the ship is swung around, and also provide means for the quick landing and embarking of passengers and parcel cargo.
(e) Damage to propeller in such steamers as above enumerated is, if anything, less likely in the case of the paddle wheel than a screw, and when damaged the former can be examined and repaired, without taking the ship out of water, by an ordinary mechanic such as a country blacksmith. It is true that by providing a well over over the propellers, as is now frequently done in shallow draft twin-screw steamers, the screws can be examined and even removed and replaced; it is not, however, so easily effected as in the case of a paddle wheel, especially if the water is not smooth at the time.
On the other hand, paddle wheels and the engines driving them are almost of a necessity heavier, and occupy more space than obtains when screws are used, as there is a limitation to the number of revolutions for a paddle wheel far below that of a screw. The engines, etc., in the case of side-wheel steamers occupy the most valuable part of the ship, and the straining action on the hull is much more severe and has to be taken at a part less able to withstand it than is the case with screw engines. The ship occupies more space in a dock or circumscribed water, and the paddle-boxes are exposed to sea and wind to an objectionable extent. These arguments do not, however, apply to the stern-wheeler, but, on the other hand, that form of paddle-boat has not the turning or manœuvring qualities of the side-wheeler. It is claimed for the side-wheeler that she is steadier in a sea-way and does not roll to the same extent as a screw, due to the gyroscopic action of the wheels and shafts, and to the fact that the plane of the paddle floats strikes the water, in rough weather, at a considerable angle from the vertical. The ship is thereby prevented from oscillating so much as she otherwise would; as sailors say, "the wheels pick her up when she rolls."
The latter argument, however, is no sufficient set-off to the serious objections to the paddle wheel in sea-going ships, and it may be taken as practically certain that it will never be employed again in them; and further, that the tendency to-day is for the screw to have a wider application and to supplant the paddle even in the services named, where it is employed with some advantage, perhaps largely owing to the present disposition and fashion to employ the cheap and light turbine as the prime mover, which, besides possessing those qualities, permits the use of the screw, and actually requires it to be of quite a small diameter.
On economic grounds the screw would always be preferred to the paddle, for in prime cost and upkeep, as well as in total efficiency of propeller and machinery, it has the advantage; but of late years the paddle engine has been so much improved, and such care has been taken in every way to make it and the wheels highly efficient, that the difference is not nearly so marked as in the days when the paddle man treated the screw with contempt, and the lethargy arising from the scant scientific knowledge as well as self-sufficiency, kept both him and the screw man from making the advances in construction years ago that both have achieved in later times."

K urgess
24th January 2007, 19:54
The original paddle wheels had fixed floats and were known later on as the “radial,” in contradistinction to the “feathering” wheel, which gradually displaced it.

The radial wheel, however, is still used where lightness, cheapness and simplicity are prime factors in determining the choice. In small light draught river steamers, especially those plying on waters remote from engineering workshops, and where even the wayside blacksmith is not known, the radial wheel obtains, and its comparatively low efficiency has full compensations. But even the radial wheel has been modified from its original form, by making the floats in steps or by making the parts of the arms to which the floats are at an angle with the inner part attached, so that the plane of the float at entry is nearer the perpendicular than it would otherwise be, as shown in fig. 20. Of course, floats so placed are at a disadvantage on leaving the water, as they tend to scoop the water above the normal level; but in practice this action is not appreciable in the fast-running, shallow dipping wheels of the stern-wheeler, and by no means outweighs the gain in efficiency by the better angle at entry. Of course, such a wheel when running “astern” must have a very low efficiency, but as this is only at intervals and for a short time, it really does not matter. Sometimes the floats are set so that their planes are at angles with instead of parallel to the axis, so that “entry” may be more gradual and the tail race or wake may be diverted from the side of the ship. It is very doubtful, however, if there is any substantial gain made thereby; and such improvements as are possible by such means are more often hoped for than proved, as in most other cases of propeller modifications.
In early days when paddle steamers made long runs and burnt so much fuel that the draught of water was considerably less at the end of the voyage than at the beginning, the radial wheel permitted of the floats being shifted outwards so as to get a more suitable dip when the voyage was half done. In the light draught river craft of to-day, when conveying cargo or in other ways experiencing much difference of draught, the position of the float can be altered to suit the immersion of the radial wheel, which is a distinct advantage.

The feathering wheel, the idea of which was originally suggested by Hooke and patented by Elijah Galloway, was undoubtedly an improvement on the radial, inasmuch as the floats could enter the water and emerge from it without shock and with the least amount of disturbance; and throughout the immersion they are acting solely in accelerating a stream of water in the right direction for successful propulsion. Moreover, by mechanically and automatically placing the floats and maintaining them in their true position for maximum efficiency, it was possible to have a wheel of much smaller diameter than with radial floats. Perhaps this is best appreciated by noting that the paddle steamer “Scotia,” the last of the famous Cunard Atlantic paddle liners, was of 4000 I. H.P. and had a radial wheel 40 feet in diameter, whereas the modern paddle steamer "Violet," of 4070 I.H.P., has a feathering wheel of only 21.5 feet diameter; and the most powerful paddle steamer ever built, the “Empress Queen,” of 11,000 I.H.P., has a wheel only 17 feet in diameter. Not only is it an advantage for the ship to have the smaller paddle boxes, but to the engineer it is a distinct gain to have small wheels, for he then must and can run at a much higher number of revolutions, and is thereby able to develop the power required with smaller and, consequently, cheaper and lighter engines.
The “Scotia” ran her trials at 15 revolutions, the “Empress Queen” at over 50, while to-day, with large and small paddle steamers, 52 to 58 and even 60 revolutions is common practice: consequently as much as 8 I.H.P. is developed per ton of machinery as against 4 I.H.P. with the “Scotia.”

K urgess
25th January 2007, 23:14
"Paddle wheels with outer rims (see fig. 18), always used in the early days, are sometimes preferred now and are even necessary for certain services, inasmuch as they guard the floats from contact with floating wreckage and driftwood, whereby they would be damaged and their mechanism very likely be put out of action, if not smashed. Such a wheel, composed as it is almost exclusively of rolled bar iron subjected to the simplest of mechanical treatment, is necessarily a cheap one, and one easy to repair either at sea or in port. No one part of it is very heavy, and being bolted together it can be taken to pieces in situ when required, and every part could be made or renewed by a common smith without any special appliances. On the other hand, its extreme diameter is greater than that of the other wheel, and should floating “raffle” or wreckage get entangled in the wheel, more mischief may arise than if there were no outer rims. Fig. 18 shows the construction of such a wheel as carried out by one of the leading engineering firms forty years ago for an Irish mail steamer of high speed. The floats in it are more numerous than is the rule now, and the floats are comparatively short for their breadth.
Paddle wheels without outer rims are now almost exclusively used for high-speed steamers, on which the speed of revolution is now so high and the power of the engines so large that much greater care is necessary in both the design and the workmanship of them. Fig. 19 is the elevation of the wheel of a modern cross-channel steamer, showing how heavy are the arms required to work successfully under these modern conditions, and how carefully they are notched into the inner rim in order to get the assistance of the other arms to sustain their load when it is a maximum; with such a wheel there is more clearance for the float to oscillate and less liability of the wheel itself coming in contact with a bank when running in narrow or shoal waters, because of the absence of the outer rim. Such a wheel, however, is costly and somewhat heavy, and it cannot be so easily repaired, but the floats can be more readily removed and replaced when required."

billyboy
26th January 2007, 00:18
some very interesting facts there marconi. thank you for posting

K urgess
26th January 2007, 21:09
"Position of Wheels.—-The “Charlotte Dundas,” the earliest steamship, had a single wheel in an aperture at the stern; in fact, she may be said to have had two sterns with the wheel between them (see fig. 2,). The “Claremont” had a pair of wheels, one on each side, nearly amidships, an arrangement spoken of as “the side-wheeler” as contrasted with “the stern-wheeler” of the “Dundas”. Bell's “Comet” of 1812 had two pairs of side wheels (see fig. 3,), an arrangement not then new, for ships with numerous wheels worked by other power than that of steam had been tried before. Almost the only other, and certainly the most striking, repetition of the two-pair wheels, was when Sir Edward Reed adopted it in the cross-channel steamer “Bessemer,” 340 feet long, built in 1874. He did this to enable the centre part of the ship to be entirely devoted to the swing saloon of Sir Henry Bessemer, which was intended to prevent sea-sickness by always remaining level.
It is interesting to note that in the case of the “Bessemer” the wheels were 130 feet apart, and when going at full speed the after or following pair made 30 revolutions and the leading ones only 27 per minute, the I.H.P. exerted being about the same for both pairs of engines. It is not likely that two pairs of wheels will again be tried on a steamship.
Stern-wheelers generally have only one wheel (see fig. 20), though usually driven by an engine on each side instead of on one side only, as in the “Charlotte Dundas.” Such wheels are very often radial, and sometimes even without a box or any covering. The wheel is, however, sometimes divided into two so as to admit the engine between them. This is a convenient and economic arrangement, as may be seen in fig. 21, for the engine-room is boxed in and so confined that one man, without leaving the driving station, can keep his eye on and even attend to every part of the engine. By fitting two engines, an independent one to each, the ship is much more manageable and less liable to be at a standstill from damage to wheels, and the extra cost of such an arrangement is trifling compared with the advantages derived from it.
Three paddle wheels are sometimes fitted to the stern of large beam shallow draught ships so as to get greater propulsive power. The wheels are, of course, in line axially, and are generally so arranged that there is a crank between a pair of wheels—that is, there are two cranks between the three wheels.
A remarkable boat of this kind was built at Wiborg in Finland in 1885; she was 110 feet long, 25 feet beam and 4 feet deep, and drew only 22 inches of water. The cylinders were 14 inches and 28 inches diameter and 5 feet stroke. The paddle wheels were 12 feet diameter, and when running at 37 revolutions per minute attained a speed of 11 knots with 350 I.H.P.
Single wheel amidships is generally associated with the name of Captain Dicey, who advocated the system so successfully that a cross-channel steamer named “Castalia” was built and tried on the Dover-Calais station in 1874. On her proving a failure his backers got a larger and more powerful one on the station, named the “Calais Dover,” but she too proved a failure. The fact is, each ship really consisted of two hulls set far enough apart to permit of the working of the one huge paddle wheel and connected above water so as to appear as a single ship. The immersed skin was about double that of an ordinary ship, and the channel between the hulls, subject to the inflow to and the wake from the wheel, offered great resistance, as did also the cover of this channel in bad weather.
Central-wheelers were tried in quite early days, and on account of the protection afforded to the wheel and the extreme beam tending to steadiness in a sea-way, it was no unnatural thing that the arrange­ment should attract attention for cross-channel service in the days when it was thought the screw was quite unsuitable for such service."

That's the end of the chapter on the history of paddle wheels. Aren't you glad you asked!
If anyone wants to know the criteria for paddle wheel design and the calculations required including "the locus or path of the paddle float centre" please let me know.(POP)

billyboy
27th January 2007, 06:58
Well!...What can one say!... in the words of the show business folks "follow that then folks"
Brilliant research Mrconi. many thanks for taking the time and trouble to post all this info for us. I owe you a large one for this mate.

K urgess
27th January 2007, 12:02
No problem, Billyboy

Scan it and email it and I'll drink a toast to you tonight.[=P]

Nasdrovja
Kris

billyboy
27th January 2007, 12:12
Pouring a bottle of 12 year old rum into the scaner now mate. hope its getting through the wire to you Marconi...LOl

K urgess
27th January 2007, 12:36
Cheers, Billyboy

Printer started burping so I opened the lid and out she popped.(EEK)
More like 40 year old rum, mate.(Thumb)

A bit faded 'cos of the distance but palatable non-the-less.(Pint)

Johnny Depp eat your heart out[=P]

Skol
Kris

Derek Roger
27th January 2007, 16:10
Thanks for the posts Sahib . Made good reading and the feathering gear sketch is very good .
For the engineers if you look closly at the sketch you will see that the bottom float connecting rod is ridgid ( it is called the driving rod and is a much heavier constuction than the rest ) The others are lighter and pivot at their connection .

Derek

jimmys
27th January 2007, 16:42
The Waverley has the feathering gear with no outer rim. As I said previously in Scotland the drive rod is the radius rod and the whole system is a "Jenny Nettle". Failure of the drive rod and the paddle is useless.
There is some good photos of this system on the PS Waverley site. The whole paddle was unshipped recently.

best regards
jimmys

see psps1.mysite.wanadoo-members.co.uk/2005.htm

Bearsie
27th January 2007, 17:31
absolutely awesome!!!
Thanks Marconi Sahib :)

How does one convert rope horse power to bollard pull?

In the end I suspect that the propeller won out cause its lighter and cheaper, and can be hidden at the end of a ship, inclusive all the machinery.
Just as it in turn was encased in the Kort nozzle and now we are moving to Jet drive, which is really just a propeller inside a housing.

RayJordandpo
27th January 2007, 20:58
absolutely awesome!!!
Thanks Marconi Sahib :)

How does one convert rope horse power to bollard pull?

In the end I suspect that the propeller won out cause its lighter and cheaper, and can be hidden at the end of a ship, inclusive all the machinery.
Just as it in turn was encased in the Kort nozzle and now we are moving to Jet drive, which is really just a propeller inside a housing.
When I served on the ocean going tugs in the seventies and eighties we would go to either Rosyth or Rotterdam (Europort) to physically carry out bollard pulls on new buildings, ('Lloydsman' for example) These two ports had specially strengthened bollards for that purpose. All the major towing companies carried out these tests except the German company 'Bugsier' who apparently worked their bollard pull out on paper. I can't remember the actual conversion factor but I'm sure it was something like one ton of pull to every one hundred horsepower.
rayjordandpo

Derek Roger
27th January 2007, 21:10
The Waverley has the feathering gear with no outer rim. As I said previously in Scotland the drive rod is the radius rod and the whole system is a "Jenny Nettle". Failure of the drive rod and the paddle is useless.
There is some good photos of this system on the PS Waverley site. The whole paddle was unshipped recently.

best regards
jimmys

see psps1.mysite.wanadoo-members.co.uk/2005.htm

Also Jimmy you would be more than familiar with question 32 in "Ship Construction " Mac Gibbons M.o T Orals .
My only flirt with paddle steamers was the regular crossing on the B.L.Nairn from Newport to Dundee . There was an observation ; lounge where one could see into the engine room . As a kid I was facinated and would do a few trips back and forth watching the movements of the engineers and also watching the paddle floats going round and round . I credit that is probably the main reason I decided I wanted to be a Marine Engineer .

Derek

jimmys
27th January 2007, 21:26
Hi Derek

I had a deep involvement with the PS Waverley over a long period and as she still sails I do not wish to say a lot. Old ships are trouble with a capital "T".
A beautiful ship. Look to the site for a good view. The "Jenny" is mentioned

best regards
jimmys

K urgess
28th January 2007, 00:43
Last word from me and then I promise to shut up.

The second paragraph on paddle wheels is mainly concerned with design calculations such as -
"an old rule for number of floats is
Number of floats = 60 √R
(where R is the revolutions per minute of the wheel)"
That's the simplest one.
There are three more diagrams that I've attached to round it out.

The explanation that goes with figure 24 reads thus -

"The path is easily constructed by remembering that while the wheel is turning round on its centre it is advancing with the ship; and since the tangential velocity is at a higher rate than the horizontal advance of the ship, there will be the loop at the immersion period, due to the differences in direction and velocity, so that the horizontal difference in position of a point on the path is the measure of the acceleration imparted to the water in the time taken in effecting the movement."


I don't think we need to bother trying to understand that. (EEK)

Derek Roger
28th January 2007, 01:10
In your first sketch Sahib on the previous thread it clearly shows the "Driving Rod " or as Jimmy calls it the " Jenny Nettle " at the bottom of the picture . All the other float connecting rods were pivoted and in many caes the pivot bearings were wood " Lignan Vite : others were bronze . If the " Drive Rod Failed " ( broke then the floats would have no eccentric control and just flop all over the place and result in very poor efficiency of the floats and quite a lot of noise .

jimmys
29th January 2007, 19:28
In Glasgow we call person who follow the PS. Waverley, "NUTTERS". They have an interest in the Paddler. It is not a derogatory term, being more complimentary to their enthusiasm for the vessel.
I can see Marconi Sahib has the potential to join this club, his attention to detail would be of immense use.
I am a nutter

Best regards
jimmys

K urgess
29th January 2007, 23:24
Thank you ,Jimmys, an honour.

I certainly qualify as a "Nutter". (LOL)
Not necessarily in the purely paddler and Waverley sense although I must confess to a soft spot for paddlers. Comes from using the Humber Ferry from a very young age. Worst thing that happened round here was that b..... bridge. :sweat:

I just happen to collect old books about marine engineering, shipbuilding, radio, etc., ad nauseum. I can usually find enough information on a marine subject to bore the pants off anybody within range.

So watch out. I'll be back to a thread near you.[=P]

Cheers
Kris/

billyboy
29th January 2007, 23:46
I have often been called a nutter, never realised quite what it meant before...LOL
Marconi...i will be watching a thread near me for your next highly informative episode with baited breath. consider yourself as one of the sites assets.

Chillytoes
23rd March 2007, 11:32
Billyboy's original question of nearly two years ago has been fully covered, but after seeing Marconi Sahib's transcription fom Seaton, it struck a chord. I have a 1909 copy of that book and I checked further amongst my collection and came up with a 1918 copy of Sennet & Oram's "The Marine Steam Engine" and an 1885 copy of Main & Brown's "The Marine Steam Engine. Designed Chiefly For the Use of The Officers of Her Majesty's Navy". Both these books make note of disconnecting gear. Sennet & Oram say - "In paddlewheel tug-boats, gear is usually fitted to enable the wheels to be disconnected from each other, and each engine worked independently, to facilitate the manoeuvring of the vessel." The even older book talks about three separate methods of disconnecting paddle wheels. Maudsly's, Seaward's and Braithwaite's methods are described. So this nutter reckons that question is well and truely answered. As to the question of bollard pull, haven't found anything yet, but will keep looking, Bourne's 1855 "A Treatise On The Screw Propeller" has a detailed comparison of the "Rattler"/"Alecto" trials and there may be something there. These were two warships, so I doubt that there is a comparison of bollard pulls.
On the question of "Rattler"/"Alecto", the series of trials were designed to test the effectiveness of the screw, as was seen as a more attractive proposition from an operational perspective. All the usual benefits were already noted; didn't alter the waterline, not susceptable to gunfire, always immersed so effeciency not affected by change of draught, rolling etc.
Well that will do this nutter for a bit.

K urgess
23rd March 2007, 11:46
Green with envy, Chillytoes.

Especially the Bourne. Can't afford one, wish I could. Maybe I'll get lucky again at auction.[=P]

allantcondie
4th April 2007, 13:53
The Thames incident springs to mind when discussing independent paddle wheels. The majority of excursion steamers from the 1870s on had a single paddle shaft. Paddle Tugs however had independent paddles. There were exceptions - the rule seems to have been to do with length to beam ratio. The three Tay Ferries Newport, Sir William High, and B. L. Nairn had two sets of Compound Diagonal engines but these were supposed to be coupled by a clutch when the vessel was in passage. In practice they didn't usually bother!
The Galloway Saloon Steam packet Co's Stirling Castle (1899) had disconnecting engines to allow for maneuvring up the windings on the approach to Stirling.

The Diesel Electric and Diesel Hydraulic ferries on the Forth had independent paddles chain driven by separate electric motors and the Southern Railway Farringford had a machinery layout based on the first two Forth vessels Queen Margaret and Robert the Bruce.

K urgess
5th April 2007, 00:31
Another quick word or two on the subject.

1/ Attached is a picture of the engines of the Great Eastern in the Science Museum from "Shipping Wonders of the World" published in the 1930s. The interesting bit is the shaft between the 2 engines. There appears to be no connection between the two paddles at all.

2/ From Tod and McGibbon's "B.T. Elementary Questions and Answers for Marine Engineers" published in 1914 -

103. What is a "Disconnecting Paddle Engine?" At what place is the disconnecting effected? How is it accomplished? In which of the cranks of a disconnecting engine are the crank pins fixed?

Ans. A disconnecting paddle engine is two engines so arranged that they can work together or seperately, thus enabling one engine to be worked ahead and the other astern, which is necessary when quick turning of the vessel is required. The disconnection is effected at the crank pin, a large disk being used which forms the inner crank web; on the back of it is a clutch which slides on feathers or keys fixed firmly on the shaft; in this disc is a hole to take the crank pin. It will thus be seen that it can be moved backwards or forwards on the shaft by a suitable lever, and so the hole in the disc is made to engage the crank pin when both engines are working together and disengage with the pin when working seperately or in opposite directions. The crank pin is always fixed in the outer crank so that one engine may drive each wheel when disconnected.
The second attached shows the clutch arrangement.

Kris

allantcondie
12th April 2007, 15:12
I note the reference to "Nutters" - this name originates from the mate during the first season of preserved operation John McCallum. The late Ian Muir, once chief engineer on the Waverley, and I created an aerosol spray to deal with over enthusiastic "Nutters" called K.A.N.

The label stated:

"A product specially formulated to protect the life, sanity and virginity of the disressed british seaman - One two second burst corrodes stopwatches, fogs camera lenses, renders magnetic tape adhesive and reduces stupid questions to a choking gasp".
It has recently been reformulated to include destruction of mobile phones!

Supplies were kept in the Pursers office and on the Engine Room Platform!(K)

gdynia
12th April 2007, 15:24
When I served on the ocean going tugs in the seventies and eighties we would go to either Rosyth or Rotterdam (Europort) to physically carry out bollard pulls on new buildings, ('Lloydsman' for example) These two ports had specially strengthened bollards for that purpose. All the major towing companies carried out these tests except the German company 'Bugsier' who apparently worked their bollard pull out on paper. I can't remember the actual conversion factor but I'm sure it was something like one ton of pull to every one hundred horsepower.
rayjordandpo

Ray
Heres a webpage

http://www.steerprop.com/bollardpullcode.pdf

swilsonburgess
16th April 2007, 07:01
I do believe the Royal Navy had some very large Aircraft Carrier Handling Tugs (Director class ), powered by Twin Diesel-Electric units which gave these vessels the capability of independent power/direction to each paddle.
the vessels were quite large - 60 foot beam ! (I have a photo of one of these `beasties` when I dig it out I will post it.

Of civil paddler tugs I do recall the `railway` midships with a small "quarry" type wagon laden with chain/ scrap iron etc which was used to raise the paddle clear of the water for manoeuvering !

Have a Good Week

Regards and Good Health

Steve Wilson-Burgess

swilsonburgess
16th April 2007, 14:17
With reference to my last message , you may find the following info of use ;-

Royal Navy Paddle Tugs/ Aircraft Carrier Handling

HMS DEXTEROUS,DIRECTOR,FAITHFUL,FORCEFUL,GRIPPER,GRIND ER

Tech Spec LOA 157`
BEAM 60`
Draught 10`
Grt 473t

4 x Paxman 12YHAXZ 585bhp @ 1000rpm
coupled to 340kw Generators driving 2 x 600vDC Propulsion motors
each producing 800bhp @ 212rpm !

not bad eh

the last one was scrapped c1980

Have a good week

Steve Wilson-Burgess

Tony Breach
16th April 2007, 14:31
Hi Steve,

Any idea what the rpm of the wheels was?

Tony

BarryM
16th April 2007, 15:30
... or the bollard pull?

allantcondie
16th April 2007, 16:21
Paddle shaft revs were around 60rpm.

Bollard pull - I'll look this one up and report.

Tony Breach
17th April 2007, 20:02
Thanks Allan,

Campbells' BRISTOL QUEEN & CARDIFF QUEEN ran normal full speed ay 48rpm on the shaft.

An interesting article about a model paddler from an Australian contributer in April's Marine Modelling International magazine. It refers to independent wheels and indicates that a wheel running astern pulls the hull down in the water while a wheel running ahead pulls the hull up in the water. I'm still thinking about that one. With experience of the BRISTOL QUEEN in the Avon & the Cardiff "drain" I know how quickly they will sniff out the bottom if on one side of the channel; they would almost go sideways into the bank. Great ships though.

Tony

Bruce Carson
17th April 2007, 20:08
I read somewhere that the bollard pull for these diesel tugs was 10.
Does that make sense?

http://www.nelmes.fsnet.co.uk/paxman/faithful.jpg

Bruce C

allantcondie
17th April 2007, 22:21
Incidentally, Waverley normally revs at around 50 these days but she is much higher out of the water since the rebuild - more at her designed depth. The smaller the wheels the faster the main engine revs. The LNER Marmion had small wheels and revved at around 65 rpm.

swilsonburgess
19th April 2007, 13:58
Hello Tony & Barry
Unsure about RPM or Bollard Pull on these beasts, will have a dig in the archives and see what appears !
Have had some right `finds` of late including a ration book from the 3 day week ! two wallets yielding two bus tickets and a fiver !

Have a Good Week

Regards and Good Health

Steve Wilson-Burgess

Tony Breach
20th April 2007, 10:38
Kris,

Yours with the illustration of the GREAT EASTERN machinery is interesting. In Dennis Griffiths' Steam at Sea, illustration 2.18 on page 22 shows this engine from the side. On page 24 Griffiths comments upon it: "The engine had four cylinders and the paddle shaft two cranks, there being two inclined cylinders connected on each crank". Note that engine & shaft are singular.

In a case where there are two independent paddle engines I am assuming that there must have been a substantial bearing with housing, support & bracing at the inner end of the shaft in order to minimise stress on the shaft bearings of the engine & the bearing arrangement where the shaft passes through the shell plating.

Tony

K urgess
20th April 2007, 11:00
Tony

I agree that it looks strange and I couldn't make up my mind whether there was a connection or not between the two shafts.
Close inspection suggests that the valve box actuators (?) in the middle may be on a crank making the shaft solid from side to side.
A different angle of the model would help.
As you say the two cylinders at each side appear to be operating on the same crank. The two cranks are 120 apart and the valve actuators a further 120 apart and operating in opposite directions making it look very complicated, to me anyway.
I'm not a mechanical engineer and so look on steam engines with wonder especially since they seem to work totally without the benefits of electricity or electronics.[=P]
The bearings between the cylinders and the paddles would have to be extremely hefty in any case to support a central crank like that. I hate to think what sort of stress was placed on that valve gear in a heavy sea.

Cheers
Kris

Chillytoes
20th April 2007, 12:22
On the question of the Great Eastern's paddle engines, in Beaver's "The Big Ship", there are a couple more illustrations to ponder over. On page 50 are two sketches of the crankshaft. The upper one, which I have seen many times elsewhere, shows the paddle shaft after forging. This a only half of the shaft but it shows one end web with a hole, presumably to form a connection with the other half, but there does not appear to be a similar hole in the other end web. The lower picture shows the half shaft being lifted on board and again, one web has a hole and the other web now seems to have a hole as well, but it is not very clear. On pages 52/53 is a large reproduction of the again often seen drawing of the paddle engine room. Like the other illustrations, one must be aware of some artistic licence, but there does seem to be a connection between the two sets of engines. There are two rods to be seen going down through a hole in the intermediate platform and it looks like they are driven by a crank or eccentric joining the two shafts. There's also a photograph on page 54 which looks to be taken on the tops of the paddle engines and which seems to show a connection. I will have to re-read the book (and Dugan's "The Great Iron Ship") to see if there is any reference to disconnection. Apart from her ability to carry the whole Atlantic cable, she was considered to ideal for cable-laying due to her paddle/screw combination being able to keep a steady station. Disconnecting paddles would be even better. Hope this sets off another flurry from my fellow nutters!

Chillytoes
20th April 2007, 13:47
Just looked at Emmerson' "John Scott Russell" and on page 119 the same drawing of the paddle engine room appears along with a photo of a model of the engines. I suppose the model is from the Science Museum. Anyway, it clearly shows that the two shafts are connected and two rods are driven by the crank connection. Also shows two large collars(?) outboard of the oscillating engines and thses might form part of a disconnecting gear. These are also visible in the photo I referred to in my earlier post. Maybe if someone can look at the museum, the matter will be cleared up. Sort of.

allantcondie
21st April 2007, 17:36
All Paddle steamer engines, even from early times, have what look like collars outboard of the engine crankshaft on each side - the paddle shafts are connected to these, usually by six or eight bolts. The shafts are 'floating' to a certain extent and the couplings have a slight flexibility to allow for movement of the ship's hull in a sea.

Chillytoes
27th April 2007, 12:30
On closer inspection of the images mentioned above, I find my first assumption on the Great Eastern's paddle shaft is wrong. It was in fact one major forging with another journal added to each of the outer webs. This journal carried the bottom ends of the cylinders and at its outboard end had this unusually large diameter thick circular plate with what looks like a clamp around the outer edge carrying the other end of the crank. The model photo shows this ring and another ring outboard of that one, then a bearing before the shipside bearing. The drawing of the engines shows a cotter in the web for the engine crank which can also be seen in the photo. I accept what Allan has said above although there is no evidence of such connection in any of these images. In the model pic, the outer ring on one side appears to be cast with webs as does the inboard side of the inner ring on the other side of the engine. All rather interesting - and confusing. (And maybe obsessively boring.)

Chillytoes
27th April 2007, 12:57
Oh use your brains, Mr Toes!!
As soon as I posted the above message, it hit me. I have a catalogue of the Science Museum's Marine Engineering collection and of course it describes the Great Eastern's engines, both paddle and screw. It notes either port or starboard element of the paddle engine could independently run the paddles as each was a complete unit. Further, "The paddle shafts were connected with the engine shaft by powerful friction clutches, the elaborate power driven disconnecting gear shown on the model was, however, were never actually fitted." There is also a note - "The two balance weights on the model were added in the Museum Workshops, and did not exist in the actual engines." Why were they fitted? I guess that these may be the large collars/rings. (Better leave it there, don't want to drive everyone mad!)

Derek Roger
27th April 2007, 23:09
I think this question has been put to bed a long time ago .
A lot of paddle steamers had independant drives which was ideal for manouvering ( as in ferrries with short crossings or tugs )
For deep sea vessels ther was an advantage in connecting the two paddles to allow for more easy steering on long trips where with both paddles driving at the same speed the rudder was the only means of steering . The idea that having independant driven paddles caused the vessel to become unstable is rubbish .
Similarly when one had a vessel with only one engine then the paddles had to be connected ; there was no other option !
Derek

allantcondie
1st May 2007, 08:43
The instability idea came from the "Thames Incident" of which I have still to find out where this was documented. This was the result of all the passengers being on one side of the vessel which developed a considerable list. When the paddles were started in opposite directions the 'corkscrew' effect caused the vessel to capsize.

In my experience, those passenger ferries with independent paddles had no problems, but the norm was, of course, to have a single engine and a single paddle shaft on most sea going vessels.

senior pilot
6th November 2007, 13:00
take a look at my web album on picasa you will see a pic of h.m.t. director at full speed album called :- port auxiliary service tugs alex

Jim S
17th November 2007, 21:02
The "paddler question" continues to bug me as I am sure I had read somewhere of the requirement for passenger carrying paddle vessels to have both paddles connected.
I have just found a website that relates to John H Amos the last paddle tug built for civilian ownership in UK.
She was built by Bow McLachlan of Paisley, Scotland for the Tees Conservancy Commissioners. Before her completion the builders went bankrupt, however the liquidators finished the work. Completed in February 1931 the customer refused to accept her for a further two years due to her speed not being to specification.
Her machinery consisted of 2 - compound steam engines developing 500 IHP
Steam at 125 psi by 2 coal fired two furnace Scotch boilers.
The piece of the document that is of relevance to the ongoing discussion is -
Unlike all passenger carrying paddle steamers the John H Amos was able to work each engine independently. This gave the manoeuvrability necessary for a tug. The article goes on to say - It was found that on passenger vessels when approaching port the passengers went to one side to disembark. If the engine were then worked independently the uneven distribution of weight could capsize the vessel.
Certainly this article gives credence to those of us who had this niggling feeling that there was some reason for the policy. Of course with the introduction of larger more powerful triple expansion engines the size of these engines within a certain beam made the whole thing academic.
The John H Amos came under ownership of the Medway Maritime Trust in 2001.
I can find no account of any passenger carrying vessel actually overturning.
The only incident that I can find of a paddle steamer oveturning in the Thames was as a result of a collision where the paddle vessel was hit on a paddle box and overturned with loss of life.

keithjplumb
30th December 2007, 10:11
In my days at Sealink Parkeston quay, we did some work on an ex isle of wight paddler "the Farringford" this had paddles each with it's own Giant DC motor. The motors could be controlled independantly to steer and manouvre her [I dont recall any other steering gear being fitted]and presumably they could be rotated in opposite directions as required. She was identical to the eye fore and aft and could be driven either way round.

Keith

Peter D Hingley
31st May 2008, 17:53
I can't quote 'ex cathedra' on all paddle tugs though I get the impression that most if not all had a single drive shaft driving both paddles. The late Dr Waine's magnificent book will be the obvious reference but that is at home and I am not ! Remember the greatest advantage of paddlers is shallow draft. The ones that definitely DID have independent drive were a class of Admiralty diesel tugs (perhaps the last paddle tugs ever built ?) which were built for manouevring aircraft carriers and nuclear s/ms; they were built with low air draft so that they could fit in under the angled flight deck of a 'carrier . Thus the tug wuld be secured alongside close to the big ship's Centre of Flotation (about which her hull naturally rotates) and by going ahead on one paddle and astern on the other could almost spin her on the spot. Obviously this would be done at low speed !
Or to quote Calouste Gulbenkian; 'My car can turn on a sixpence, whatever that is !'.
Peter D Hingley

chadburn
18th June 2008, 17:44
Sorry Billy Boy, the John H Amos has two diagonal compound engines in her and you could spin her round on a sixpence, she did have a large "dog clutch" in between the main engines but it was never engaged, spent a period of time on her as her Chief Engineer (her youngest and the only one still alive!!) in the early 1960's whils't waiting for another ship and as a favour to an old friend, her normal Chief had been mixing the tilly lamp glass cleaning Meths with "Johnny Pine" and had fell down the jetty steps breaking his arm. She was at one time involved in a smuggling operation until the Customs rummaged her in the late 1950's

chadburn
18th June 2008, 18:00
To add to the above we did carry passenger's, the John H was not just a Tug which is why it carried a qualified Engineer for Insurance requirements and the reason why I was aboard her, paddlers were really best used as stern tugs as the paddles acted as brake "shoe's"

eddyw
20th June 2008, 23:53
Great Eastern didn't have independent wheels. However she could still turn round in her own length. Paddle engine run slow astern, screw engine slow ahead with rudder hard over. Speed could be controlled very precisely down to about 1Knot by similar means yet still maintaining steerage way. This was why she was such a great success as a cable layer.

chadburn
2nd July 2008, 07:22
You could "boost" the engines on the John. H. by means of the impulse valves, these put Boiler pressure steam into either the H.P. or L.P. cylinders (either side of the pistons) without going through the valve boxes. The Impulse valves were operated by two levers at the Engineers control position on each engine, the secret of course was knowing when to pull and push the levers otherwise it had the reverse effect and slowed the engine down!!

dwdb
24th September 2008, 08:19
Minor correction - Talisman had FOUR diesel engines - Generally one was out of use for maintenance. The single electric motor (800 Volts) was located between the paddles on a solid shaft.. I was a crew member on this ship in 1952

GWB
24th September 2008, 11:04
Valayer, you are right during my early apprenticeship worked on the BL Nairn doing annual surveys and repairs, both engines were independent for maneuvering ability. The Sir William High was laid up in the dock waiting buyer never worked on her but did couple trips across the river on BL Nairn on the plates.
Brings back old memories.
Cheers
George

Derek Roger
24th September 2008, 14:48
Valayer, you are right during my early apprenticeship worked on the BL Nairn doing annual surveys and repairs, both engines were independent for maneuvering ability. The Sir William High was laid up in the dock waiting buyer never worked on her but did couple trips across the river on BL Nairn on the plates.
Brings back old memories.
Cheers
George

Watched the BL Nairn many a time as a school kid while having lunch on the shore at Newport . She used to really struggle when it was windy .

Derek

Albert Bishop
24th September 2008, 19:55
The Eppleton eestate did indeed have independently opperated paddle wheels. I remember her well, from her days as a Tyne tug. Now in a maritime museum in Frisco
http://www.nps.gov/safr/historyculture/eppleton-hall-history.htm
Worth a check for anyone interested Cheers Albi
( Hope this works)

Cangarda
12th October 2008, 17:45
An interesting discussion. In the research I've been doing for an article on railroad ferries on the Kennebec River in Maine, the railroad lists their first boat, in 1867 as having a single engine 34" x 8' on 75# steam. The assumption must be that the paddles could not operate independently, perhaps one could be clutched out but it's doubtful they could be opposed.

Later boats all had two engines, and as this photo illustrates, they could be opposed.

Photos also show they all had centerline rudders. Now, the Kennebec is a big, tidal river with currents up to 4 or 5 knots, at right angles to the ferry pens. How the devil, even with opposing rotation could the boat be maneuvered into the pen? The photo shows the strength of the current on this approach and it seems she is crabbing sideways.

I'm a ship handler and understand what's involved. It seems that having a rudder placed in the slipstream of each paddle would be very helpful, but I've never seen any example of this being done. What am I missing? How did they do it? spc