The Writing on the Wall

ChasD
2nd August 2008, 18:24
Over the course of 25yrs or so of 'sparky-ing', I was privileged to witness what I feel were the peak, the best, of the years over which the profession was in existence. From the early years when the Oceanspan and the Siemens T10A were king, through the development of the big beasts, Crusader, Conqueror and so on, the introduction of telex, right through to the introduction of the Satellite systems. I also had the privilege of being involved in some of the earliest introductions of this equipment, first of which occurred in Teesport on 'Amoria/GCXU' in/around 1964, when a bunch of Marconi 'Whizz-Kids' descended on the vessel, took away my T10A (it was a Siemens/AEI station at the time) and installed a pre-production Crusader. Shell was in the habit of offering random ships as test bed facilities, great for me, a new toy to play with and the loudest shout on the ocean - if a little unreliable at times!
At that time the system seemed to be growing and developing, so when, I wonder, did the writing first appear on the wall, to indicate that 'The End Was Nigh.' It may have been as early as 1970 when a similar bunch of excited chaps arrived on 'Mangelia' to install an experimental creature called 'Lincompex' (Linked Compression Expansion), together with a breadboard rig (literally screwed down on a board) of the 'Selcall' (Sequential single frequency calling). This, they instructed, I was to use to carry out daily tests with Portishead – (at their convenience rather than mine as it turned out !). They were good enough to provide also a tame technical type whose brief was to instruct me sufficiently so that I didn’t break it and accompany us on a trip as far as Capetown. (Charming young chap, “Hello!” if he’s still around!) An interesting system, I don’t believe the Lincompex ever seriously got off the ground, though the selcall system became the call system for telex.
I believe that the first commercial Telex system on a UK ship may have been the one fitted to Drupa/GRVH, giving her a telex number that was something like 445500. Perhaps someone can confirm/correct, if List of Callsigns are available for the period? Similarly I think the first Satellite system was fitted to Genota (pics attached), when the inaugural commercial Inmarsat transmission was somewhat disfigured by my appalling typing ! I understand that QE2 also carried out pre-production, pre-commercial tests. Very shortly afterwards, tentative unmanned radio room tests were initiated (again with a breadboard rig) and from there, the rest was inevitable. Personally, I was more interested in the tech stuff than the basic watchkeeping, so having all this stuff to play with was great – at the time! 'Hoist by ones own Petard' springs to mind. Did anyone else have experience of the Lincompex or other early stuff ?

Shipbuilder
2nd August 2008, 19:30
I went to sea in early 1961 & remained there until late 1992. On my first voyage, the mates tended to make a great thing of "sparks are not necessary & will be gone within the decade, flag communication is equally as efficient as radio communication - unnecessary personel etc." Apart from that, that were pretty obnoxious & left no stone unturned in making life miserable for me. Apart from Captain & mate who never (thank goodness) spoke more than a few words to me all the way to Aussie & back.

I loathed progress - I loved valves & I detested "whizz kids." I still became 2nd in large passenger ships, but walked out of the MED course in 1973 (Southampton) because not only was it beyond me, but I wasn't interested enough to make the effort to understand. Immediately I walked out (having thrown my career away according to Principal), I became relieving "Electronics Inspector" for same passenger ship company in Southampton. Didn't like it (although it was easy enough) & returned to sea - promoted again! Then had to leave when passenger ships were sold. Joined cross-trades company & got three new ships in a row & managed well enough - existing, but not happy. Then was invited to join "throwback" company where they never wanted me to go back to college, listened to what I had to say (treated me better than I have ever been treated before at sea). & provided me with HF telex, fax, satcoms, sat nav, embryo maritime e-mail, all the test equipment that I requested (without argument about cost)& all the trimmings - loved it & my lack of electronic education never held me back one bit. Remained happily with them until getting fed up (not their fault) after 31 years at sea. Now love messing about with model ships, radio valves etc. Today, I made my 3rd variable capacitor (two of them attached)- how about that - life well-spent because I never really believed "the writing on the wall!" I always believed in what I was doing & acted accordingly & I was NEVER "hoisted by my own petard!"
Bob

Bob

K urgess
2nd August 2008, 19:50
It was writ large on the side of the first VLCC I joined with a MED.

ChasD
2nd August 2008, 22:24
Hi Shipbuilder Bob ! You make me jealous ! I have no-where like the skill to do that, there was a time when I could change a 16 legged bug in a double sided PCB without a second thought! Now? Now, it is said, I can't put a tractor through a barn door without a white stick! But being something of a historian, my interest is in trying to delineate the history of the profession I once loved, the profession I will always be at heart. Keep on with what you are doing !
Best for now ... Chas

Radioroger
19th August 2008, 07:00
Hi ChasD

You asked whether anybody else had experience of Lincompex and early systems. The following may be of interest

I was involved with Lincomex. It was installed on the QE2 as new fitout and I was at the factory for training.
From memory it was not too very successful on the QE2. It was great when there was no QRM but the problems was that the data channel was carried within the normal speech passband and therefore subject to QRM from other ships. This would make the system useless when this happened.
Interesting the QE2 was issued with spare Lincompex units ! That is strange for non-essential equipment whilst other more essential equipment did not have spares !

I know that Lincompex was tested on ships prior to the QE2 but cannot remember if it was Brocklebank or Cunard ships or both.

As regards telex on ships. In 1969 QE2 was fitted with both an early version of ARQ telex and also the British embassy communications system Picolo.

The Picolo system was used to transmit the Daily Telegraph newspaper to the ship in the form of a punched tape to a siemens teleprinter. The receivers had to be very stable in frequency and phase. Each had a digital frequency sythesiser instead of using thelocal oscillator.The punched tape then went into the print shop . The newstories and headlines were sent seperately. Photographs,adverts and crosswords were placed on the ship prior to the voyage. I still have an example of one of these early newspapers dated May 26th 1969 with 8 sides. At the time I thought the newspaper a bit small. However it is a lot better than the newspapers currently on the QE2 or other cruise liners I have cruised on ! Mind you it need a lot of effort to produce a newspaper.

An alternative way of transmitting the newspaper was using the Plessey ARQ system. Again from memory there were problems with QRM. If it could not get perfect copy it came to a complete halt as it kept asking for repeats ! Under these conditions the Picolo was better. It is sometime better to have poor copy than no copy !

I think the Plessey ARQ may have also been used at times for normal teleprinter traffic instead of straight RTTY but I am not so sure about that.
We certainly had teleprinter links via HF to Portishead a lot of the time.

GPS. Perhaps it is not so widely know that in 1969 QE2 was fitted with a version of early satellite navigation. It was based on the Military "Transit" system using the military satellites. The equipment was very large. It used a PDP-11(I think 11) computer to an ITT teleprinter. Calculation of position took ages and required experience of using the equipment. I never got round to playing with it - I remember we often had experts on board trying to make the system work ! The system used a dual frequency antenna consisting of a large distinctive double helix. How different from the modern handheld gps !

There were other novels systems such as the notch antennas - but more of this another time as this post is too long already !

Roger

Mimcoman
19th August 2008, 07:19
Lincompex was also installed at Stonehaven Radio for a time, but I was told that it was never very successful - not sure if it was problems with the gear or just not popular with the oil rigs/platforms. Anyway I never saw it used and it was dismantled shortly after I started at GND (in 1979).

The big earner at GND was the multi-channel narrow-band telex services, using Autospecs or Spectors, with 85Hz shift instead of the normal 170Hz. Twelve channels within a 2.7kHz bandwidth, so handled by a normal A3J transmitter. Each (Autospec) channel was around £1000 per month for a dedicated H24 link from a specific rig or platform to a specific onshore office. The Spector channels were about £1200, I think. Nice little earner until Inmarsat took over from the late 80s onward.

Ron Stringer
19th August 2008, 09:29
Interesting the QE2 was issued with spare Lincompex units ! That is strange for non-essential equipment whilst other more essential equipment did not have spares !



Roger,

That was almost certainly because the operational Lincompex and the spares were being provided and installed absolutely free of charge to Cunard. Angus MacDonald was a past-master at persuading gullible sales and promotional people within the radio and electronics suppliers that having the latest 'gadget' aboard the QE2 would be of fabulous promotional value to their latest baby. MIMCo's management were always highly resistant to such blandishments (how many large passenger ships were there in the 1970s/1980s compared with the number of tankers, cargo ships and large trawlers?) and argued that the average shipowner would be more likely to think that something adopted by the QE2 would be 'over the top' for their vessels.

That changed when we 'gained' a sales manager from IMR who employed a UK Sales Manager ex-B & C. They spent a small fortune providing and fitting ARQ and remote-tuning transmitters on QE2. As far as could be discerned from the (very) cloudy sales statistics available at that time, the effect on sales was nil, although the customer-entertainment and technical-support-for-sales budgets were significantly elevated (Angus did like to dine well). As soon as they left the company, an invoice for the equipment was submitted (and quickly rejected) and the equipment was dismantled on the vessel's next return to Southampton. I don't believe MIMCO made any sales to other owners as a result of the free supply of equipment to QE2.

On visits made to the QE2 radio room and the transmitter room on the upper deck, I was amazed that the ship ever passed radio survey. Remote controls to the emergency transmitter were home-made and would not have seemed out of place in a Heath-Robinson drawing. The radio operating room was an ergonomic nightmare with equipment from every supplier under the sun popped into any space available, so that an item could be metres away from its associated receiver or control unit. Those R/Os (or radio assistants as they were later known) deserved every penny they got for working in those conditions.

I don't know what the R/Os thought of their company's unusual commercial practices concerning the provision of radio equipment but (outside the ranks of eager salesmen) I never met anyone in the marine electronics industry who believed the mantra that "as fitted on QE2" would be a sure-fire seller.

Radioroger
19th August 2008, 15:54
Hi Ron

Thanks for the enlightening reply - very interesting.

It is time for bed here being midnight 50 !

I will comment more later. It might be worth putting comments on QE2 fitout under a more appropriate thread title to get more comments from later ROs as well.

All the best

Roger

Radioroger
20th August 2008, 14:06
On visits made to the QE2 radio room and the transmitter room on the upper deck, I was amazed that the ship ever passed radio survey. Remote controls to the emergency transmitter were home-made and would not have seemed out of place in a Heath-Robinson drawing. The radio operating room was an ergonomic nightmare with equipment from every supplier under the sun popped into any space available, so that an item could be metres away from its associated receiver or control unit. Those R/Os (or radio assistants as they were later known) deserved every penny they got for working in those conditions.

I don't know what the R/Os thought of their company's unusual commercial practices concerning the provision of radio equipment but (outside the ranks of eager salesmen) I never met anyone in the marine electronics industry who believed the mantra that "as fitted on QE2" would be a sure-fire sell


As regards Angus's involvement in the QE2. I am not sure exactly when this was. I cannot even remember seeing him aboard during fitting out so you are probably refering to later. The radio room project was under the overall control of Colonel Hornsby - an Army man, which may account for some of the strange decisions about fitment - at least strange to an RO !

I know that the actual planning of the radio room fitment was IMRs. I can remember the technical person in charge but at the moment cannot remember the name. You would probably know.

I am not sure what you mean about MIMCO ARQ installed and removing remote-tuning transmitters on QE2. I assume this was much later and nothing to do with the STC 1430 1kw self tuning transmitters installed by IMR initially.

Cunard/Brock certainly had a mix and match policy of equipment on board many of its vessels unlike Marconi. They totally relied on the maintenance skills of the ROs to maintain the equipment. They always recruited staff with 1st Class PMG and Radio Maintenance Ticket and who had the skills to maintain equipment and were proud to do so. On ships other than QE2, shore radio and radar maintenace staff were only called in an extreme emergency - ROs were expected to do it themselves!

I do not know that ROs ever thought adversely about Cunard/Brocks commercial policy on the fitting of equipment. It was a way of life, you did not have to have standardisation, you learn to operate the new equipment and you learnt to fix it when it went wrong !

From MIMCOs point of view the policy made no sense - but MIMCOs had huge numbers of ships with their ROs and a huge network of service facilities that needed standardisation. Cunard/Brocks was a small player and only small numbers of ROs. They did not have the service facilities throughout the world. I suspect their commercial policy was to rely on quality ROs, pay them a little more and not have to pay huge overseas service bills ! In the provision of equipment they played off one supplier against another to get a low price. The result is often a radio room with a bit of this and a bit of that but it did not matter. They did not have everything standardised so that that the local serviceman in Bombay or wherever could fix it in a few hours ! I suspect the philosophy continued with the QE2.
Why was the QE2 not IMR employed ROs like the old QE. The answer was that the Cunard freighters went over to Cunard/Brocks ROs and the Captains liked the service they got. They had ROs who knew how to fix the radar and would do do so immediately. The Captains on the freighters were also the officers on the cruise ships and so word spread ! Anyhow thats the story I was told.

You have raised a number of issues about the QE2 and its problems in the radio room. I will put them on a new thread in Radio Room called "QE2 Radio Room"

All the best

Roger

Vital Sparks
20th August 2008, 14:45
Hi ChasD

GPS. Perhaps it is not so widely know that in 1969 QE2 was fitted with a version of early satellite navigation. It was based on the Military "Transit" system using the military satellites. The equipment was very large. It used a PDP-11(I think 11) computer to an ITT teleprinter. Calculation of position took ages and required experience of using the equipment. I never got round to playing with it - I remember we often had experts on board trying to make the system work ! The system used a dual frequency antenna consisting of a large distinctive double helix. How different from the modern handheld gps !
Roger

Cunard eventually gifted this unit to Southampton College where I remember seeing it gathering dust in 1984. It was the size of a filing cabinet with a very odd looking helical antenna about 30cm in diameter and half a metre in height.

Ron Stringer
20th August 2008, 17:17
As regards Angus's involvement in the QE2. I am not sure exactly when this was. I cannot even remember seeing him aboard during fitting out so you are probably refering to later.

I am not sure what you mean about MIMCO ARQ installed and removing remote-tuning transmitters on QE2.

You are quite right about the dates; I was referring to the late 1970s/early-1980s. The MIMCo equipment was always 'additional' to the existing installations but I understand that by then a number of other changes had been made in the transmitter room. However the MF emergency transmitter arrangements were said to be original.

Radioroger
21st August 2008, 09:18
From Vital Sparks
Cunard eventually gifted this unit to Southampton College where I remember seeing it gathering dust in 1984. It was the size of a filing cabinet with a very odd looking helical antenna about 30cm in diameter and half a metre in height.

That sound like the Sat Nav unit alright - I think it was Magnvox but not sure.

This forum is wonderful - you find out all sorts of thing you would never have found out !

Did the college ever getting it running again ?
Was the POP minicomputer and ITT teleprinter with it ? You needed the ITT teleprinter to load in the computation program into the PDP as well as for readout - no VDUs then !

I have started a thread "QE2 radio room" as these subjects are probably a bit off track for "the writing on the wall".

All the best - Roger

Mimcoman
22nd August 2008, 01:47
T&J Harrison fitted their bulkers with Redifon SRN-1 satnavs in the mid-70s. They were a box about 2ft x 3ft x 6in, used ferrite-ring memory boards, and the display used loads of festoon lamps that were forever burning out. The programming was done from a punched tape. The technician who installed it had a punched tape game involving landing a lunar lander on the moon; you had to calculate fuel usage etc by entering various parameters from the front panel. First computer game I ever saw.

mikeg
22nd August 2008, 13:31
Lunar Lander games loosely based on the original software are still available for pda's mobiles etc with enhanced graphics. Quite a challenge juggling various functions such as orientation, fuel burn, altitude, velocity etc. plus dealing with the added computer malfunctions purposely written into the programme.
I know, sad innit?

K urgess
22nd August 2008, 20:18
Computer games with graphics! (EEK)
What was the world coming to!

Mimcoman
22nd August 2008, 20:44
Challenge is right . I used the landing programme for test purposes (well, that's what I said) but never managed to get down safely.

mikeg
23rd August 2008, 11:56
It was a tad easier with later programmes like this:

http://www.palminfocenter.com/news/8988/lunar-lander-simulator-developer-interview/

Good eye-brain coordination exercise.

ChasD
17th October 2008, 22:05
I believe that the first commercial Telex system on a UK ship may have been the one fitted to Drupa/GRVH, giving her a telex number that was something like 445500. Perhaps someone can confirm/correct, if List of Callsigns are available for the period?

Just for the historical record, I have now been able to confirm that 45500 was the Selcall number of the experimental rig on Mangelia. Drupa was 45501, being the first UK commercial fitting, and Darina 45502.

ChasD

R651400
18th October 2008, 06:38
ChasD, I assume you're referring to SITOR? Was a shipboard telex installation automatic ie scanning various HF SITOR frequencies or set manually for each telex contact?

ChasD
18th October 2008, 10:52
Hi ! These were the old SPECTOR installations, usually fired up by a SelCall and usually set to listen to a specific station (eg GKA) although they would operate to any suitable station. Ran through the main R/X and main T/X which it fired up automatically, though they could also monitor one - way broadcasts when necessary. ChasD

mikeg
18th October 2008, 10:55
Just for the historical record, I have now been able to confirm that 45500 was the Selcall number of the experimental rig on Mangelia. Drupa was 45501, being the first UK commercial fitting, and Darina 45502.

ChasD

Any idea regarding their respective install dates Chas?

Mike

ChasD
18th October 2008, 11:12
Hi Mike ! The experimental rig on Mangelia would have been around 1970, Drupa, I think, got it in Falmouth (Brent conversion) in 1975, Darina shortly thereafter, though this is going from memory. Got the numbers from some old traffic and the pre-made header tapes I used to carry around and have now found in the dustier regions!

mikeg
18th October 2008, 12:11
Hi Chas,

Thanks, was on Darina in 1978 forgotten the Selcall number though, good to be reminded :) I did the same with header tapes but mine got binned shortly after leaving the sea - unfortunately. Whilst talking tapes, I remember some sent messages being extraordinarily long tapewise - almost needed the size of dustbin as a feeder box..

R651400
18th October 2008, 15:52
Hi ! These were the old SPECTOR installations, usually fired up by a SelCall and usually set to listen to a specific station (eg GKA) although they would operate to any suitable station. Ran through the main R/X and main T/X which it fired up automatically, though they could also monitor one - way broadcasts when necessary.
Does one assume that outside GKA propagation skip eg mid Pacific, this expensive installation was about as useful as the two spots on my chest?

p.s. Have just seen your Spector input in gallery. Without the arrival of satcom I maintain this mode is clutching at straws by comparison to a qualified R/O.

Mimcoman
18th October 2008, 19:38
I liked SPECTOR - Thos&Jas had it fitted to all their non-general cargo vessels from mid-70s onward (first on Strategist and Specialist, then retro-fit on the Wayfarer, Wanderer and Warrior, then on the A-class container vessels). I was able to work GKA from mid-Pacific, off Vancouver, Japan, Aussie coast, etc. Sure, you had to pick your frequency according to the time of day, but then that was necessary whatever mode you were using. GKA's SELFEC service was also quite good - although you had to rely on its operaters using your TR info detailing which channels you were monitoring while in port - and also remember to retune your own receiver accordingly (I never had a scanning telex receiver).

Incidentally, I believe that the precursor to SPECTOR (AUTOSPEC) was in use on Shell tankers in the late sixties.

R651400
19th October 2008, 03:32
Thanks above Mimcoman. I was actually assuming that TOR modes were after the R/O's had been made redundant and operated by others.
Amtor the amateur version I found a bit gimmicky but obviously with ARQ and FEC almost foolproof if not slow under adverse conditions.

ChasD
19th October 2008, 06:42
Thanks for the memory jog Mimcoman, I had forgotten about Autospec! Never actually came across it in real life, dont know whether it was just a pre-production version of Spector, although in your earlier link you say it was a seperate beast ?

Tai Pan
19th October 2008, 10:15
I was at sea 1950-1960. we had a machine that decoded the info from shore stations-me.

BOB GARROCH
19th October 2008, 11:30
the writing is on the wall for all radio engineers and technicians. Modern equipment needs no input from either. Modern digital radio systems are more IT than radio. Seven layer mother boards are servicing by computer, fault diagnosed and board changed or scrapped and replaced. I am busy installing a wide area radio LAN throughout the Durban area, comprising of 5-7gig links. UNEDUCATED african installers are installing the equipment simply by mounting on to a suitable bracket, point, plug in a plastic stethescope and adjust direction for maximum tone. Plug in the Cat5 LAN cable run into office and plug that into a router. End of story there is no need for me anymore. the system is used for computer connections, streaming video, PABX VOIP, and anything else IP . Retire next year after a life of excitement in the merchant navy and radio systems throughout Africa. Go back to the navy life feet on the table reading a Lois Lamour cowboy book.

K urgess
19th October 2008, 13:17
While looking through my MED notes in a failed effort to keep up with this thread I've come to the conclusion that the writing was on the wall when I did the course in 1974.
As I said previously, it was writ large on the side of the first VLCC I joined with a MED. Trouble was it was either in a foreign language or said something I wasn't quite ready to hear. It took me 3 years to decipher and by the end I knew it was all over. There was nowhere to go except along the same road for the foreseeable future. Not just the job but the whole game had changed beyond recognition and the adventure was disappearing under a pile of boxes and barrels.

My RTT notes, which are sandwiched between facsimile and transmission lines, mention BS70261, BS72512, CCITT, Van Duuren ARQ, Autospec & ITT Unitec. All of which came in handy when sorting out computer communication in a later life but now just makes my head hurt. (Whaaa)
In 1974 the marine equipment mentioned as being "The types of equipment currently used are -
i) Marconi Autospec & ITT Unitec. These employ the same method for forward error correction using a ten element code. The system is suitable for broadcast reception.
ii) CCIR recommended equipments (recommendation 476). Commercial equivalents are known as SITOR & SPECTOR. These equipments have two modes of operation, ARQ & broadcast; both modes employ a 7 unit code with a 3 to 4, A to Z ratio. (?HUH)

All systems employed must be capable of direct connection into the public telex system, that is, the input & output to the system will be in the international telegraph alphabet number two."

It goes on to explain the various things in more detail in handwritten notes. When time allows I may add them to the directory along with other "interesting" subjects.

Never saw a sniff of it until my very last trip when the gear was being sorted out for fitting in drydock as I left.

Ron Stringer
19th October 2008, 14:13
''Selcall'' at sea began as a multi-tone calling system developed by Siemens, similar to that widely in use in the land mobile service (e.g. as used by taxi firms for many years). It involved allocating each station an identity number and providing it with one or more receivers to monitor internationally agreed frequencies on which stations would broadcast calls. Each call consisted of the identity of the called station and of the calling station. This could be used to trigger an alarm on the called station and display the identity of the calling station. Although perfectly acceptable for use on FM and by taxis, on HF it proved so prone to corruption by interference and propagation problems that the frequent false alerts meant that it quickly fell into disrepute and was abandoned. However the identity numbers allocated to this service were later also adopted as the identity numbers for a teleprinter or telex service to ships.

''Autospec'' and ''Spector'' were both made by Marconi's Wireless Telegraphy Company. ''Autospec'' was a forward-error-correcting system that used 10-bit characters made up of the 5-bit CCITT No.1 code (the 5-element characters that were used with punched tape and teleprinter used for telex) arranged forward and reverse, in a sort of mirror image. The signals were converted to FSK and broadcast from a transmitter. The receiving station could be just that, with messages being received and printed out without any need for a transmitter to be present. However if two-way communication was required, then both stations had to have transmitters available so that they could work, alternately on the frequency or frequencies in use.

All characters were transmitted twice; the received data was stored and the results of the two compared. If they agreed the character was output and printed. If they did not agree, then bits were checked; if in a 10-bit character the 1st was not identical with the 10th bit, the 2nd with the 9th bit and so on, then an error symbol was printed. If they did agree, that character was deemed to be good and the character was output and printed.

Worked pretty well and was in use for many years for point-to-point telex circuits from the early 1960s, and were deployed in the North Sea for MF (1.6 - 3.8 MHz) links from BT (GPO at that time) coast stations to those oil rigs beyond the range of UHF line-of-sight links. They were later superceded by tropo-scatter systems and satellite links.

''Autospec'' was also fitted on a number of Shell tankers in the early/mid-960s as part of Shell's experiments with data collection. Using data-logging equipment produced by English Electric and Elliot Automation, the logged data was passed to Marconi ''Editor'' FSK modems and then via the ''Autospec'' to the ship's transmitters and receivers to be sent through Portishead to Shell Centre. Went on for a few years before they lost interest (God knows what they did with all the data that was sent back).

In the late 1960s, the ITU (CCIR) searched for a system to adopt internationally to provide telex services to ships. Various candidate systems were considered, of which two were Marconi's ''Autospec'' and a system developed by Philips and the Dutch Post Office (Netherlands PTT). This was called SITOR (standing for SImplex TOR). Although it did have a forward-error-correction mode, this equipment also included ARQ. This proved more effective than forward-error and the Philips system, slightly modified, was adopted by the CCIR as the international standard for marine applications (CCIR Rec. 476).

The ARQ mode required both stations to be available for transmitting and receiving for communication to be possible. Characters were sent in blocks, each repeated twice, however the transmitting modem continued to repeat a block until it received an acknowledgement from the receiving modem (sent in the gaps between blocks). The sending station had to receive an acknowledgement before if could send any further characters. Each character to be transmitted (letters, numbers and punctuation) was represented by a 7-bit code that was made up by adding two extra bits to the character's 5-digit teleprinter code. This was done in such a way as to ensure that, in each character, the combinations of the two elements (representing the Mark/Space of the teleprinter code and the two different FSK tones that were transmitted) were in a 4:3 ratio. As long as the received characters contained bits in a 4:3 ratio, they were considered accurate and the receiving terminal sent an automatic acknowledgement. If the received data was not in a 4:3 ratio, an error was assumed and the equipment automatically demand a repeat from the transmitting equipment.

Although in principle this was a simplex system (each station transmitting alternately) and could therefore operate on a single frequency, in practice the problems on board of obtaining adequate separation between the transmitter output and the receivers input circuits meant that the service operated as a two-frequency simplex arrangement.

The FEC mode of the Sitor system used the same 4:3 code as the ARQ, which was adequate for broadcasting messages such as weather and navigational information. This was later incorporated into the Navtex service. Having only 7-bit characters it was somewhat less capable than the 10-bit arrangements of ''Autospec'' but Sitor didn't need a more accurate FEC facility since it used ARQ for all communications where fidelity was essential.

Both equipments could direct messages to a single station by use of a selective identity, both in ARQ or FEC modes (SEL FEC). This latter mode was used to broadcast messages from coast stations to individual ships in port or unable to use their transmitters for other reasons.

''Spector'' was produced by Marconi to the CCIR standard so was somewhat more up-to-date than the Philips product and sold widely to shipowners. However with its earlier entry into the market, and its adoption by the PTTs of countries eager to offer an automated telex service for ships, the Philips equipment was the one mostly used by coast stations. The Swedish PTT's Goteberg station was the first and then Scheveningen and Bern were early providers, but the Swedish were the pioneers in using fully automated stations for telex. Self tuning transmitters, signal strength-directed automatic directional antennas and DEC11 computer-controlled line connection were available long before the UK had even a single, manual Philips STB75 TOR facility.

All water long under the bridge now, but very interesting at the time. As with all such systems, international agreements take so long to finalise that the service was virtually obsolete by the time of its introduction. It had been in use for only a few years when a single company, Comsat-General of the USA went it alone and produced a ship's satellite communication terminal, avoiding any international discussions whatsoever. There beganneth the end for maritime HF communications.

mikeg
19th October 2008, 14:20
I really felt that kick-in 10 years later Kris when I was providing input to the draft submission submitted to the Secretary of State under section 28 of the MN (Safety Convention) Act 1949 for trial exemption of aural distress watch for v/ls fitted with Satcom etc. Was trying to post that typed draft on pdf but file copy too large at 76KB - could split it up over posts or scan as jpeg and reduce. Mind you it was really great concentrating on electronic repairs rather than aural watchkeeping but I always had that nagging doubt that it wasn't as good as aural watchkeeping lives could be lost.
Mike

ChasD
22nd October 2008, 09:53
Similarly I think the first Satellite system was fitted to Genota (pics attached)

Again for the historical records, we now have the Inmarsat number for GENOTA GUUY which was 1443401, and the fitting confirmed as being Aug/Sept 1979 - further back than I had thought ! The rest of the G Fleet were fitted in rapid succession as they came up for docking and all have sequential numbers 02, 03, 04, etc. Numbers come curtesy of freddythefrog, dates from my Dis Book.

Ron Stringer
22nd October 2008, 13:43
Again for the historical records, we now have the Inmarsat number for GENOTA GUUY which was 1443401, and the fitting confirmed as being Aug/Sept 1979 - further back than I had thought ! The rest of the G Fleet were fitted in rapid succession as they came up for docking and all have sequential numbers 02, 03, 04, etc. Numbers come curtesy of freddythefrog, dates from my Dis Book.

Chas,

INMARSAT didn't come into being as an organisation until 1979 and did not produce equipment standards until several years later. So if you had satcom in 1979, it was almost certainly built by Scientific-Atlanta (of the USA) to Comsat-General standards. Some time after 1979, Japan Radio Corp. produced the first non-American terminal and by the mid-1980s others came on the scene.

King Ratt
22nd October 2008, 15:38
The first RFA fitted with Satcom was RFA Olmeda in 1979. Her equipment was Magnavox and her marisat no was 1443201. There were other RFA vessels equipped after her with the numbering sequence 14411xx. We referred to Olmeda's terminal as "Orac" and it was paged once every 24 hours from ashore by the satellite operators, a pain in the neck if you were taping up a signal at that instant and the machine took over.

ChasD
22nd October 2008, 17:26
Hi Ron, It was definitely JRC, see the pics on the initial posting, and it was my understanding at the time that we were 'the first', whether that was the first Inmarsat or what I'm not sure at this range, though it was more than just Joe Shell's first and we had officials from several organisations to witness the inaugural transmission.
Thanks K.R. for the input on RFA, gives us the data that there was a parallel group there. My understanding of the number is that '144' was the country code, followed by the ship number. Self evident that there were groupings within that, but how they were based I don't know now.
At the time, I think there were only two satellites in orbit, (Pacific and Indian ?) but that is from memory. Also the data I have from JRC refers to 'Marisat' rather than 'Inmarsat'.

Ron Stringer
22nd October 2008, 19:16
... the data I have from JRC refers to 'Marisat' rather than 'Inmarsat'.

Exactly my point Chas. The original Comsat-General system was marketed under the title 'Marisat' and was nothing to do with INMARSAT, an organisation that did not even exist at that time. Comsat-General produced equipment design standards for the ground stations and for a ship station. They operated the 'Marisat' service.

Once established INMARSAT took over the co-ordination of the existing 'Marisat' services and their integration with new ground stations and services. The existing ground stations continued to be operated by their former owners, while INMARSAT adopted the existing 'Marisat' ship station standard and called it INMARSAT-A. However, not until the introduction of INMARSAT's Standards -B, C, M, etc., could it accurately be said that there were INMARSAT terminals aboard ship. INMARSAT also took over the provision and operation of the space segments of the satcom service, eventually commissioning channel capacity from other satellites already in orbit and, much later, putting its own satellites into service.

You may consider me nit-picking to point out the difference in titles, but it was Comsat-General, with its 'Marisat' terminal that did all the pioneering, entrepreneurial work and brought satcoms to the maritime world. They deserve all the credit. INMARSAT was devised after the event as a rear-guard action by the Europeans and the Russian bloc (remember this was still in the days of the Cold War) who were unhappy at the prospect of the USA having total control of maritime satellite communications to and from their countries. A similar situation exists today with GPS and the European dream of providing a competing Low Earth Orbit satnav system, Galileo

ChasD
23rd October 2008, 10:37
Excellent stuff Ron ! Clears away a lot of the fog from the half-remembered stuff I haven't even though about for 25yrs or more .... ChasD

Mimcoman
23rd October 2008, 14:04
Just on a sour note, as a grumpy old ex-R/O and as someone who enjoyed HF comms, I'm not sure if "credit" is the word I would use when referring to satellite comms.

I still await the time when a virus wipes out all the satellites and the word goes out for "trained hf operators"...

mikeg
23rd October 2008, 14:42
Just on a sour note, as a grumpy old ex-R/O and as someone who enjoyed HF comms, I'm not sure if "credit" is the word I would use when referring to satellite comms.

I still await the time when a virus wipes out all the satellites and the word goes out for "trained hf operators"...

Now that truly would be our 'Independence Day'

Larry Bennett
23rd October 2008, 15:34
[QUOTE=ChasD;257248]My understanding of the number is that '144' was the country code, followed by the ship number. Self evident that there were groupings within that, but how they were based I don't know now.
QUOTE]

There is a standard format for Inmarsat Numbers - rather than go into it in great depth, the following is the basis:

INMARSAT-A - A 3-digit country code or MID (UK is 144, 145 and 146) followed by 4 sequentially-allocated Octal numbers. No '8' or '9' was allocated.

INMARSAT B/C/M - First digit indicated the system - 3 for Inmarsat B, 4 for Inmarsat C and 6 for Inmarsat M. The next 6 digits were based on the vessel's MMSI, which again was country-based. The penultimate number indicated the number of terminals on board - '1' for the first terminal. '2' for the second and so on - and the last number was used for Inmarsat B and M to show the service of the terminal (voice, fax, telex, data etc.). So, a typical vessel with MMSI 232123000 with 2 Inmarsat C Terminals would have numbers 423212310 and 423212320, and with an Inmarsat B Terminal would have 323212310 (voice), 323212311 (fax), 323212312 (data) etc....

Special numbers were allocated for High-Speed Data (64k) for Inmarsat-B terminals which bore no resemblance to the MMSI, beginning 39xxxxxxx.

Inmarsat Mini-M, M4 and Fleet terminals have sequential numbers allocated in the 76xxxxxxx series and 60xxxxxxxx series (for HSD).

Land-based Inmarsat systems had their numbers allocated sequentially by the national authority who activated the terminal - these numbers had to be downloaded in blocks from Inmarsat HQ.

There were a few allocations which didn't fit the above, and special rules applied to these.

Hope this clarifies?

Larry B
(ex-Service Activation, BT Inmarsat Services)

charles henry
23rd October 2008, 16:29
PMG Instructior
Anyone know of Peter Prance ex R/O (Fifties) then instuctor Bristol wireless
College
de Chas

Mimcoman
23rd October 2008, 19:14
Now that truly would be our 'Independence Day'
Only if you use keys with a gap of about half an inch and an unusual (well, to me anyway) style of keying.....

mikeg
24th October 2008, 11:43
Only if you use keys with a gap of about half an inch and an unusual (well, to me anyway) style of keying.....

If working for the new SOE, key clicks like that could get you shot (EEK)

Larry Bennett
24th October 2008, 13:10
PMG Instructior
Anyone know of Peter Prance ex R/O (Fifties) then instuctor Bristol wireless
College
de Chas

He was certainly at Brunel Tech in Bristol when I left in 1979 - took us for City & Guilds Mathematics 'C' - and totally befuddled us with differentiation and integration calculus....

Regret have no subsequent info post-July 1979.

Larry B

charles henry
24th October 2008, 17:11
He was certainly at Brunel Tech in Bristol when I left in 1979 - took us for City & Guilds Mathematics 'C' - and totally befuddled us with differentiation and integration calculus....

Regret have no subsequent info post-July 1979.

Larry B

Thanks for the info Larry, he was an old school chum, and went for pmg 2 together. Great pals in Canada then he went back to glasgow to marry
his girl Connie Marshal. Lost touch with him but know he had two daughters.
Ah, memories
de chas

BOB GARROCH
30th October 2008, 12:18
To MIMCOMAN I AM SORRY TO SAY BUT MODERN HF SYSTEMS DO NOT NEED ANY SKILLED OPERATORS ANYMORE.

We have "ALE" Automatic Link Establishment.

The HF Base station sends out a tone on all the available channels. As the different remote base stations respond to the tone on a scanned channel the link quality is automatically checked and the best quality channel is selected. We have HF systems operating 24 hours throughout Africa with no link failures. We are using them for voice, email, telephone connect. For instance the police force on the border post's have 24 hour communications back to their head office.
Construction companies throughout Africa can communicate back to johannesburg 24hours a day no dropped calls. This system was developed by Motorola in case the satelites where taken out by nuclear war

Sorry to say but we are redundant.

R651400
30th October 2008, 12:42
Thanks above Bob. One has to admit verging on ingenious but how about world wide?

BOB GARROCH
30th October 2008, 13:01
Thanks above Bob. One has to admit verging on ingenious but how about world wide?

YES WORLD WIDE NO PROBLEM. YOU JUST NEED TO STRING UP THE WIRE ANTENNA ON ANY TREE BRANCH IN REACH OR THE GUTTER

BOB GARROCH
30th October 2008, 13:56
Thanks above Bob. One has to admit verging on ingenious but how about world wide?

GOOGLE MICOM 3F. THAT WILL TAKE YOU TO THE HF RADIO

Mimcoman
30th October 2008, 16:29
To MIMCOMAN I AM SORRY TO SAY BUT MODERN HF SYSTEMS DO NOT NEED ANY SKILLED OPERATORS ANYMORE.

We have "ALE" Automatic Link Establishment.

The HF Base station sends out a tone on all the available channels. As the different remote base stations respond to the tone on a scanned channel the link quality is automatically checked and the best quality channel is selected. We have HF systems operating 24 hours throughout Africa with no link failures. We are using them for voice, email, telephone connect. For instance the police force on the border post's have 24 hour communications back to their head office.
Construction companies throughout Africa can communicate back to johannesburg 24hours a day no dropped calls. This system was developed by Motorola in case the satelites where taken out by nuclear war

Sorry to say but we are redundant.
Hiya, Bob:

Aye, I know about ALE. But you can dream, can't you....

BOB GARROCH
31st October 2008, 06:07
Hiya, Bob:

Aye, I know about ALE. But you can dream, can't you....


Yes I also long for the distinctive smell of Marconi equipment.

I had to stab Marconi in the back recently Tendered against them for a 13 site 9 channel simulcast system. I won, they left South africa. I felt very guilty

R651400
31st October 2008, 07:38
GOOGLE MICOM 3F. THAT WILL TAKE YOU TO THE HF RADIOThanks Bob. I found this site interesting as it gives a more succinct overview of ALE including a reliability and comparison statistic to satcom plus tonal examples.
If I was running a fleet of ships and knowing the cost of satcom I'd be having second thoughts on my ship comms.
Hope I haven't introduced anyone to the opposition!

http://www.milspec.ca/modems/ale.html