Engine controls

Fynn
3rd April 2009, 08:51
Hello,

this is my second post in this board. I'am from Germany so my English ist not so good.

I have a question about engine controls. As i understand, a controllable pitch prop requires at least throttle and pitch control levers for operation. On several pics of pilothouse consoles there are three levers so whats the third lever for? After some googling i only found a norwegian site that shows three levers labelled (if my translation is correct) pitch control (propelleromställning), reverse gear (backslag) and throttle (motorpådrag) but a cpp doesn't need a reverse gear. Can anyone explain me?

thanks,
Fynn

this is the site mentioned above
http://hem.bredband.net/lagaren/sihmprop.htm

Steve Woodward
3rd April 2009, 17:51
Fynn,
Should the control system of a CP prop fail it is supposed to default into the full ahead pitch position, the engine can then be manoeuvred like a stop start diesel, this is what the third lever is for.

Fynn
3rd April 2009, 17:58
Thanks for the reply. i read on a site that there must be a sort of clutch control for starting and stopping the engine. with a full forward-neutral-back lever you have both de-clutching and emergency operation options.

JoK
3rd April 2009, 22:59
The CPP system does not necessarily default to ahead, dependin on the installation they also default astern.

Fynn
4th April 2009, 07:04
Thanks for the reply. I have read in an MAIB report about the grounding of a Ro-ro vessel that the CPPs went into Full Astern default setting when the vessel had a blackout.

Does this affect the "FPP-emergency-operation"? If i have understand the principle this would give 100% power astern and somewhat reduced power ahead, as with a "standard" FPP (100% ahead, less astern). Is this right?

The report mentioned above also brings another question. On the pictures of the control levers you only see two of them...for two engines! As these levers are designated Pitch levers, i assume that the vessel operates with fixed throttle settings selected from the engine room? Right?

http://www.maib.gov.uk/publications/investigation_reports/2009/moondance.cfm

JoK
4th April 2009, 11:43
Too early for FPP, no idea what you mean there.
But on a loss of the CCP hydraulics, the blades on the prop would flip full astern, you would only get the power that the engines are putting out at the time. Normally on a blackout you would lose your engines as well when the electric pumps went down.

Most CCP systems work with a combinator, that the power is regulated automatically with the pitch, which prevents the engines from being overloaded. On some systems, you can manually split the combinator to fine tune the power settings for more fuel savings.

Fynn
4th April 2009, 12:39
Thanks for the reply.

FPP = fixed pitch prop. Okay, i try to explain what i mean. If the CPP pitch actuator fails, the blades are set to a definded pitch setting by means of a spring or so. The CPP effectivly becomes a FPP, right?
In his post Steve said that there is sometimes a shifting gear to use the prop in the classic Forward-Neutral-Reverse style. Now if the default pitch is "Full Astern", you have full thrust astern. But if you shift to Reverse, you have thrust forward, but how much? I don't think that a FPP delivers the same thrust into both directions.

Hope this makes clear my question..

JoK
4th April 2009, 16:45
What Steve said is the the engine is started in either ahead or astern for manuevering. You will not have full power. Someone else may have more recent dealings with this and give a better answer.

Fynn
5th April 2009, 07:01
Thanks for the reply.

I interpreted the answer that the third lever is the equivalent to the gearshift in a standard fpp installation therefore allowing to use the inoperable cpp in the forward/neutral/reverse fashion. A start stop diesel works similar but at a more complex level, as far as i know. While a reverse gear just changes the rotating direction of the shaft, a start stop diesel is stopped, the camshaft shifted to change the rotating direction, and started again, requiring more time and lots of starting air.

JoK
5th April 2009, 11:24
Right.
Normally this is an emergency function in the ER. Not a bridge function.The EOW has to go to the engine to reverse the engine.

billyboy
5th April 2009, 13:17
Never had to work in the engine room of a ship with CCP's.
Therefore I find this thread interesting and informative.
My last motor ship had direct drive, no gearbox. Stop engines and restart in reverse to go astern

JoK
5th April 2009, 19:35
My last 5 or 6 ships were diesel electric. It's been 17 years since I worked a CPP vessel. Where does time fly?(Fly)

Fynn
5th April 2009, 21:52
During my searching and googling through the web i found few informations about older CPP. Most interestingly the best were contained in investigation reports on the MAIB or similar sites.

http://www.maib.gov.uk/cms_resources/aquitaine.pdf

There are also some sites about the systems used on Scandinavian trawlers, unfortunately in Dansk, Swedish or Norwegian.

http://annanyborg.dk/blog/motorbetjening

And if you search on the homepages of major suppliers you also find some detailed infos about modern CPPs, those using combinators as JoK mentioned.

http://www.manbw.com/files/news/filesof9230/AT2000_PCS_p9023.pdf

But the most questions were answered through this thread, thanks.

JoK
5th April 2009, 23:13
I only gave the very basic details. Each system-Kamewa or Lips - is different.

Fynn
6th April 2009, 06:33
In the file about the Alphatronic 2000 is a diagram showing the relations between pitch, engine speed and power demand (s. 8) as well as a short description of the operation modes.

The modes seem to be more or less the same for older models like that:

http://www.boatnerd.com/news/newpictures03/April-15-2003-(29)-Menomine.jpg

Found also a similar one made by Berg, see the attachment (screencap from http://www.onnettomuustutkinta.fi/uploads/decgz5t4.pdf).

One large lever for coarse and a small handwheel for fine adjustment of the pitch. The Kamewa combinator is visible on several photos of bridge consoles.

http://www.alide.com.br/artigos/eithne/eithne-003.jpg
Copy&paste, the direct link on the pic won't work.

Fynn
10th April 2009, 19:07
Older model

http://www.yachtworld.de/core/listing/displayPhoto.jsp?&photo=13&boat_id=2036359&boatyr=1908&boatname=Custom+Steel+Expedition+Trawler&photo_revised_date=1235603225000&photo_name=Wheelhouse+Helm

Blue in Bim
8th June 2010, 12:09
Think you will find the third lever is for a clutch to engage the CPP control box. This allows the engine to be started without turning the shaft and prop.

eldersuk
9th June 2010, 00:02
The Kamewa system which I sailed on (many years ago) was operated by a pneumatic combinator arrangement which operated on the pitch control hydraulics and the engine governor simultaneously. With this arrangement you got constant engine RPM with varying pitch. There was also a 'pitch shedding' system to deal with overloads.
If power was lost, the propeller went into default full ahead position and as there were no interlocks it was necessary to double check the propeller hydraulic pump was running and the propeller in the neutral position before starting the engine.
The whole lot was operated by one lever on the bridge.

Derek

Mike S
9th June 2010, 12:24
I have operated both Lips and Kamewa in tugs many moons ago.

Lips had a clutch in/out lever, pitch ratio lever and and ahead and astern. You clutched in with the ratio lever on minimum (50%) and ahead / astern on 0 pitch. We then increased to around 70% pitch ratio to get away from the berth and the as the tug gathered way if we were just wandering around the harbour we left it there and worked ahead and astern as required. If we were needing full speed we would take the prop to full revs and then increase the pitch to 100%. We would decrease pitch when slowing down and then when back around 70% start coming back on the revs.

Close quarters 50 % and revs as required and towing was 78% and revs as required. Revs on first and off last...............

On memory the Lips went to zero pitch on failure however it is a hell of a long time ago and I could be wrong.

Kamewa had clutch in on zero pitch. Increase to working revs and work the pitch as required. Easier to use and once again we just used 78% for towing and 100% free running. Went to full ahead on failure ( I think!). The engines were all omni-directional.

Boy that stewed the grey matter..........we got rid of those things in the eighties! (Smoke)

Naytikos
10th September 2010, 19:42
Posted by eldersuk:
The Kamewa system which I sailed on (many years ago) was operated by a pneumatic combinator arrangement which operated on the pitch control hydraulics and the engine governor simultaneously. With this arrangement you got constant engine RPM with varying pitch. There was also a 'pitch shedding' system to deal with overloads.
If power was lost, the propeller went into default full ahead position and as there were no interlocks it was necessary to double check the propeller hydraulic pump was running and the propeller in the neutral position before starting the engine.
The whole lot was operated by one lever on the bridge.

Derek

I sailed on a VLCC with two similar Kam-e-wa set-ups.
The engines were started with propellors at zero pitch and control was then tranferred to the bridge. 'Tick-over' was around 90rpm and the revs increased with pitch to 112 at 100 percent.
By talking nicely to the Chief, one could get another 5 rpm in an emergency.
For manouvering we used 50% ahead and astern as 'full'.
It was possible to select maximum rpm (i.e. 112) by means of a switch beside each control lever, in which mode the lever would still control pitch alone.
A generator could be coupled to the starboard shaft; when this was engaged, that engine automatically ran at max. rpm.
Power sensors reduced the pitch as necessary.
The propellors turned inwards.
Neither system ever failed, but to satisfy DNV on one occasion, the hydraulics were shut-down to prove the pitch defaulted to 100% ahead.
There was normally no need for a large reserve of air so the vessels were small; 3 or 4 starts would have been the limit.

randcmackenzie
10th September 2010, 23:18
The Lips' propellers on the Seatrain gas turbine ships failed to Full Astern.

Gulpers
11th September 2010, 18:40
The Lips' propellers on the Seatrain gas turbine ships failed to Full Astern.

I remember this happening in Weehawken, NJ, on one of the Asias. (EEK)
I vividly recollect the accommodation ladder being swiftly raised clear of bollards, and the self-tensioning mooring winches whining whilst "doing their own thing" until the offending shaft was stopped! :sweat:

surfaceblow
11th September 2010, 19:42
I was on one ship the lost of air or control voltage put the CP unit to full ahead while the lost of hydraulic pressure put the CP unit in full astern. You could jack the CP to what every position you wanted at the Oil Distribution Box.

Joe