I refurbished a model from someone who had one as we were asked as a club ( so I got the task ) to build one for a chap who lived local for his retirement as he had done several tours of duty on the RTTL boats We were only given a couple of months notice the chap lent us a book called Sailors of The RAF it had several different types of boats in it

Thanks Doug. Yes that is the account of the demise of 2760 that I remember. I have been unable to find any information regarding her active service however.
A few years ago I was fortunate enough to be given a conducted tour of 2757 at Hendon and was able to get photographs of the internals of the wheelhouse and engine room. I haven't been down recently but I hope she gets preserved under cover. Work had been going on to replace some deck planking and fill some holes in the hull. With the weight of engines removed hull distortion should have been eased a bit. Regards, John

Hi Boocock,
Have you seen this Page?
http://www.ournewhaven.org.uk/page_id__1928.aspx?path=0p69p87p104p
Some interesting stuff about 2754 and 2760 from 'folks who were there'!
Cheers, Doug 😎

hi ya there Boocock

I have just relocated some of the files I had from when I did my build of the RTTL and I came across these two photographs of the 2760 Launch and I am sure I have some written work somewhere about her. I will have a look - but - some of my 'old' files are on a computer hardrive from the old computer


www.rafboats.co.uk



John

I too started a model from these plans back in 1958 when I was a member of the Hull branch of the Radio Controlled Model Society. I got as far as skinning the hull and intended to mount a marine glow plug engine as per the design. College, wife, kids came along and the model got put on the shelf. When I retired 10 years ago own it came from the shelf but I found that the original cascamite glue I used had turned to powder. To cut a long story short I carefully dismantled it and rebuilt to the stage where it is almost finished (I never seem to completely finish any project, as my wife will confirm). I have kept the single prop shaft design with two rudders. It performs well driven by a ReMax? electric motor and Sanyo 2400 battery pack. I decided to number it 2760 as I found a photo of this vessel (attached). Only later I discovered that there is very little history available. Apparently she slipped anchor, drifted onto rocks and was scrapped. If anyone has any more interesting information on 2760 I would be pleased to hear from them.

As an ex Rhodesian I find it strange that John should think the armament on a RTTL involved "troubles in Rhodesia" which is totally landlocked. The Naval activity that occurred was the Beira oil blockade by the RN some eleven miles offshore neighbouring Mozambique - which was unsuccessful except for closing down the Umtali refinery - causing my cousin to lose his job....(Oil then came through SA). No RTTL could have stood those sea conditions for long

The RAF also sent a Javelin squadron to neighbouring Zambia - The RhodAF Hunters & RAF Javelins used to do dawn patrols wingtip to wingtip down Lake Kariba - when asked by a RhodAF pilot as to what the RAF pilot would do if ordered to attack - the response was "have immediate radio failure"...........If A RTTL was set afloat in Kariba from Zambia Whitehall would have been fully aware that it would have been almost instantly blown out of the water by RhodAF or the RR Artillery should it venture out. So not very likely - also the it would have been a nightmare journey as most of Zambias good were delivered through Rhodesia..........The other routes would have been impassable and air delivery does not seem feasible.

The only other Naval activity involving Rhodesia occurred during WW1 when the Launches Mimi & TuTu passed through on their way to Lake Victoria to do battle with the German gunboats. They were guided by a Rhodesian "Big Game" hunter who had proposed the whole thing in the first place but he left after an argument with the eccentric Commander Spicer Spencer the RN had decided to put in charge..........

Thorneycroft built two small gunboats for use on the Pungwe river by Rhodesia - (the river is only navigable some 20 miles inland - well within Mozambique)- but I have never found any record or documentation for them other than a small item in a Thorneycroft history article read somewhere long ago.............

I have found very few books on the R.A.F. Marine branch. The one you quote is perhaps the best.
The other one I enjoyed, although it is more of an auto-biography, is "Boat in the Blue" by W.D. Pereira.
Not very long but I enjoyed it.
Rowen

Thanks for telling us your wonderful career experiences with these boats at RAF Mountbatten.

As an Air Cadet I visited them at Mountbatten one Saturday in the mid 1970’s and got dragged behind one when doing my parachute/dingy training in the mid 1980’s! up in Holyhead Harbour!

I bought the book on eBay last night so I can’t wait to read more about their exploits with us Aircrew!

Thanks again. Graham 😎

Thanks Graham

I am sure you will find the book interesting, I learnt a lot particularly about the difficulties in rescue in the war.

I have a vested interest in you liking this message as I am one point away from promotion from 2 nd class to 1 st class, actually looking at the note on the LH side of my screen this message is worth two points, so shall have promoted myself.

Your project has got me into a bit of research into the RTTL's. When I was at Mount Batten there was probably about 5 there then. My billet was on the third floor and we overlooked the Sound, when a RTTL came in it had a very characteristic sound, even with the engine no doubt at a low speed.

We used to do daily radio checks on them, but did not get rides, as they usually, when they went out it was for some time and it was not appreciated if you disappeared for all day. We used to get lots of rides on the Range Safety Launches as these did dingy drill for air crew and you could arrange to be doing a radio check, when they were going out beyond the breakwater to dump the pilot into the sea with his un inflated life dingy.

I did have one day out on a Mk 2 RTTL, but only across the sound and then to anchor there for the day on a nuclear attack exercise. I was glad to get back after rocking back and forward for six hours, it would have given the crew a lot of enjoyment if I had been sick.

I did have another much more enjoyable ride on the one remaining Napier Sea Lion powered Mk 1A RTTL that was still at Mount Batten, I think it had been kept for historical reasons and had not been modified to fit Griffons. As far as I was aware it was never used operationally, although we did daily radio checks. One day I found out that it was to be given a test run so arranged to be on it when it went out on test. It was a lovely sunny day and the sea was calm, we got outside the breakwater and the engines were opened up but the trip at speed did not last very long as one of the engines failed, but we still had two left so could return to the Cattewater safely. It may have been the last day that a RTTL ever ran on Napier power.

Thank you so much for this. I was on the verge of buying the book so I will definitely get it now. Graham 👍

Having a further look through " RAF Air Sea Rescue Service 1918-1986" there is quite a detailed account of the demise of 2754 which I have attached.

It would seem unlikely to me that anyone would have taken the risk of attaching an explosive charge to it before it finally sank. In my time when involved with the RAF marine craft activities, some 15 years before the loss of '54, there was very little of any interest to any foreign power on board, other than perhaps the engines.

I do not know if the main long range radio system was ever replaced as in 1961/62 it was the system used by the RAF in the Second World War i.e. 1154 receiver and 1155 transmitter. On my radio course at Yatesbury we were told that you will never see one of these in service so we spent the two days allocated to this equipment listening to the BBC on the receiver. Luckily there was a civilian engineer who knew these units and he kept them going.

Hope so. We would find it interesting.
Will be posting Episode 1 of mine on RTTL 2762E shortly.

Graham.
Brilliant.
You really have a good restoration project in your hands.
I would love to get my hands on your motor and give it TLC.
I am afraid I like so many others on this site I really believe in the ethos of don’t replace it if it isn’t broken.
Good luck and Yes, go for the blog.
Regards Bill.👍🍷🍷

Thanks Bill. John messaged me to say exactly the same thing earlier so I’m going to go with the consensus of trying to keep as original as possible. I’ll follow the webpage guide that was sent earlier and try and work through a restoration of the Graupner. Is it worth me starting a Blog on the site? Graham

Hi Sidestick.
Honestly.
I wouldn’t be too keen to disregard the existing motor.
It will remain part of the character of your boat,very important.
It is so easy to throw out the old and put in a new one,which is not always the answer.
I have a motor in one of my corvette’s that is 40 years old ..It’s as good as new.
Yes,! If is giving you troubles and you can’t get parts,then,when that occurs,replace.
As I said,and Doug reiterated give it a good session of TLC and see how it goes.
It’s all about, preserving what you have in many cases.
Regards Bill

Those photos are excellent John. Although my model looks fantastic for some unknown reason the builder constructed it without the flying bridge! It just has a flat roof. Graham

hi there, I have been going through some of the files that I have and I have come up with some rough photographs of the flying bridge of the RTTL - these are courtesy of Christian (MTB Hulls). Christian is a great source of information for these boats. There is another photograph which I put on - its an oddball one - its an RTTL fitted with a gun on the stern cabin roof. I believe this was done when there was trouble in Rhodesia (remember those days) .

John

Have long admired those pictures, your model is a work of art! The propeller story is interesting. I watched a video on Utube of one and decided to cheat and fit contrarotating screws to mine. Had experienced very sensitive steering on my Brave Borderer and thought that might help reduce it.

Thanks John. You have certainly put a lot of effort into strengthening the hull! Graham👍

Hi there

If we really do want to be a 'purist' about these vessels.

They were renowned for splitting their hulls as they crashed into waves. This was due to the fact that the propellers rotated in the same direction - causing the boat to corkscrew and dive into the oncoming wave. To counteract this, there were several attempts - one being to fit a triangular wedge shape at the stern of the hull and if you look at one of the photographs I have put on - you will be able to make out at the stern above the rudder a very slim wedge shape this was an RTTL that was being scrapped.

The second thing they attempted was to add a 3rd layer of planking to the bottom of the hull. This wasn't very successful either.

Just some food for thought. Also, here are a couple of my build photographs and the motors I put in - and the wedge I put on the stern.

Also a couple of blueprints which you may already have of the vessel.

John

Your models already far exceed mine Rowen👍
Keep it up.
😎

Thanks Doug. Will try to live up to your standards!
Rowen

Sabre also came much later Rowen,
BTW
Congrats on your promotion, long overdue!
New insignia attached.
Next step the 'Scrambled Egg hat' 😁
Cheers, FLEET//😎

Definitely Sea Lion. The Sabre was a H 24 Cyl designed for aircraft use.

Guess if he was there should be more accurate.
Doubt you would forget where your boat sank out from under you!
Rowen

Hi Rowen,
Sea Lion - Sabre?
i don't think so, the Sea Lion was 12 cylinder W block ca 500HP, the Sabre was a 24 cylinder engine with 5 to 7 times the power of the Sea Lion. (2200 developed to 3500HP).
Cheers, Doug 😎

Hi John. Thanks for all the great information and suggestions. Yes, the builder did a fantastic job but for some reason the ‘flying bridge’ is missing from the model? Today I was loaned an original Model Maker December 1958 magazine complete with the plan! I’m going to make copies for future reference. Thanks again !

Hi Rowen,
Just found this on the BMPT site
"I served on 2754 Gibraltar 1971 to 1974. She was a great boat shame about her end. After her bow got stoved in in the straits she was towed by the Navy stern first but too fast she sunk and they destroiyed her with depth charges due to the equipment she was fitted with "

Biscay or the Strait of Gibraltar?
Yer pays yer money and yer takes yer choice!😉
Cheers, Doug 😎
http://www.bmpt.co.uk/rttl-2754_topic736.html

Hi RNinMunich. Many thanks for all your advice and suggestions. I already found the website with all the photos, especially covering the sinking. I was also intrigued to read that it was ‘depth charged’ to avoid its onboard equipment falling into the wrong hands!

As far as I would like to keep the boat original to its builder I am under no illusion that the Graupner 1713 is likely to be more trouble than it is worth and so I actually think the best way forward would be to replace it with a suitable new type motor, ESC and battery as a complete ‘matched’ power plant! I’m not worried about having it blitzing around the pond at ‘scale’ speed but more akin to a bit of performance matched by a good endurance.

So, what I really need from everyone is:

Which specific motor?

Which specific ESC?

Which specific battery type/pack

I already have five fully working 3s 2200 11.1v Lipo batteries in my armoury.

Thanks again.

PS we don’t talk about BA but the opposition, VA!😎

My aircraft background shows through! Was Napier Sea Lion not Sabre

Had read somewhere she was in transit from Gibraltar to Blightly.

Exactamente Rowen👍😀
But Sabre or Sea Lion engines?
Container or no container; it can get pretty damn rough down there for a little boat or any ship!
What the heck was she doing there??
😎

Hi Doug,
2754 sank in the Bay of Biscay, thought to have collided with a floating container.
She was a Mk 1B, originally with 3 x Napier Sabre engines, shafts and props etc.
Most were later converted into the Mk 2 style with 2 x RR Griffons and 2 shafts etc.
Rowen

Hi Sidestick (BA?),
2754 was a Mk 1B RTTL; LoA 68', beam 19'.
So at 1:24 your model must be 34" LoA. Right?
Max speed was 40kn, cruising speed 33kn. See attached specs.
40kn is a very respectable speed so could be regarded as 'speed boat' 😉
See attached pics of 2754 underway.
Attached pics show her underway with at least her forefoot out of the wet stuff.
BUT pics 1 and 2 show what might happen if you have too much weight (SLA?) forward.🤔
The original boats had three shafts but I assume you are going to retain the single shaft for nostalgic reasons. OK👍
So you will need a fairly meaty motor, which I'm afraid that 1731 is not, and a battery and ESC that can deliver a reasonable current for a while.
That 1731 motor is rated at 6V, current draw On Load 3.3A, efficiency 43%, RPM OFF Load 4500. So I would expect a relatively sedate performance from it.🤔
To get anywhere near scale performance you will need to keep the boat as light as possible, i.e. NO SLA batteries!
So what is Scale Performance??
Rule of thumb is; square root of scale x max speed of original.
Here: scale 1/24, Max speed of original 40kn. So scale speed is (1/4.9)x40 = 8.1kn, which is a pretty fair trotting speed!
Frankly I don't believe that that motor is man enough. Three might have managed it though!
Personally I would go for a brushless motor; around 30xx/1000 to 1500kv, and 2S or 3S (7.4 or 11.1V nominal) LiPo battery but I appreciate your wish to keep the model true to the original builder👍
(Actually I would have rebuilt it for 3 shafts, but that's just me - I respect your wishes.)
And you may not want to get into the complications of LiPo batteries.
So if you retain that motor I would use a 5 cell 6V NiMh battery.
Given a 3.3A current draw an NiMh of around 6000mAh (6Ah) capacity should give you just under 2 hours running time.
More if you don't run full chat all the time😉
NiCads are very infra-dig these days due to the poisonous aspects of the cadmium. You'll probably have extreme trouble trying to buy them these days anyway. They have rotten self-discharge and memory effect characteristics as well.☹️

BUT: before you start connecting batteries and testing I would strongly recommend that you -
1 Dismantle and check the motor, seems to be just bolted together, check the brushes for wear and clean and polish the commutator - that's the copper bit with lots of segments that the brushes rest on 😁
Polish up with Brasso or ladies nail polish sticks. NOT a nail FILE, they are too rough.
When restoring vintage motors I first soak them in WD40 overnight to loosen up the bolts etc.
But in this case be careful to keep the WD40 away from the brushes - just in case they go soft 😭
At least oil the shaft bearings as Bill says before applying any volts to the motor!!
2 Dismantle the propshaft and check for wear at both ends, and rust at the prop end!
At the very least inject some light machine oil or even silicone grease before running any tests.

Re ESC: Given the current rating of the motor of 3.3A a 10or15Amp ESC should be more than enough; as Bill says Mtroniks Viper 10 or 15. Don't forget to fit a 5 or at most a10A fuse in case the prop gets stalled by weeds etc.
Apropos prop! I would change that for a 3 blade brass prop which is more in keeping with the originals.
For a 34" boat probably 35 or 40mm.
Bon chance mon ami👍
Cheers, Doug 😎

Sounds like a great project.
I am just wrapping one up. Am using a similar scale GF hull from MTBHulls fitted with 2 Brushless motors and a LIPO battery.
This gives good speed and she planes easily. Will be writing a brief blog shortly on this site.
Would agree with others, Lead acid batteries would be too heavy. Have not used NiCad, but been disappointed with NiMh.
Decided a couple of years ago to "standardize" on LiPo cells, as these give the best power density for weight. They do require carefull looking after, but find them worth the trouble.
There is a huge amount of information on the web. One site is RAFBoats, which has some very good pictures.

Hi Sidestick.
It’s great that your getting such a good balance of help and suggestions.
I agree 💯% with John re the battery.
I wouldn’t use the lead acid battery personally,primarily because of the weight. You would have to fit quite a lump centrally,and that probably will be a space problem.
Too far forward and you will end up with a submarine.Too far aft and you will have a speedboat!!
A good Nicad or Nimh will be just the job.
Again if you don’t have one they can be purchased from all the outlets aforementioned or on Amazon which is where I purchased two the other day at a cheaper price for the same product 👍👍.
Really would be good if you can do a refit blog to keep us all posted.
Regards Bill.

hi there,
sidestickflyer
for my twopenneth worth, I myself would stick to what Scratchbuilder has suggested. Try and keep your model as original as possible. I googled the motor and came up with this link - https://www.rcgroups.com/forums/showthread.php?2582383-Graupner-Nautocraft-motor-voltage - and its an 'old' Graupner motor.
As far as using the 'old' lead acid batteries, I would steer away from them as much as possible - and try and go for the NiCad style batteries. They are lighter and also can take a bit more punishment.
If you go on to my profile on this website and have a look in the harbour, you will see I built the same model a while back.
I use 2 MTronik motors in mine; also the hull construction is extremely light. The other thing I have noticed about your model, the gent who built it, must have known about these particular boats as its the only model I have seen (apart from a few others) which incorporates the towing winch in the back cabin.
Let us know how you get on.
John

Cornwall model boats is another spot to look for models and parts.
Rick
https://www.cornwallmodelboats.co.uk/index.html

A video sounds a great idea - looking forward to seeing it. Best of luck with the restoration.

Hi All

Sorry made a mistake for RTTL number in photograph should have been 2753.

Hi sidestickflier

I was interested in your project as a long time ago I was a National Serviceman at Mountbatten ( Plymouth ) from May61 to April 62 where was an Air Wireless Fitter, we did not have any aeroplanes but the RAF boats were fitted with aircraft equipment. As I had been, prior to my enforced service to the Queen, employed in the aerospace industry, I had some technical drawing experience, consequently I became the only person in the drawing office, this was better than going round the boats doing the daily radio tests. My main task turned out to be to fit the new UHF radio to a RTTL, the intention of it was to locate and recover sono buoys. Because of the high frequency used the signal was very directional, so the RTTL was fitted with a pair of multi dipole aerials. I never saw the end of the project but I have a book " The RAF Air Sea Rescue Service 1918-1986" that has a picture of RTTL 2754 with these aerials, which I have attached ( sorry its upside down but I have forgot how to change it ).

I have been a member of this site for a long time and supposed to be building a HSL 100, but since the lock down and having got involved in too many other things it has not gone forward for some time, hopefully I shall get back to it. As far as I know RTTL 2757 is in the RAF museum at Hendon but I have not been there for a long time and it was in a sorry state last time I saw it. From my other interest in aerospace museums, the arts university educated curators being put into positions of power are buggering up our heritage and destroying priceless items with their "political correct" activities, so it is even more important that us model makers keep up the good work. There is one thing about model boats is they last, look at all the Fire Boats there are about still and they were the inspiration of this wonderful Web Site, it reminds me I had better make a donation.

Good luck with your restoration.

Thank you so much Bill. I sold all my model boats about a decade ago apart from my yacht and having just taken early retirement I’ve decided to start over again. So, over that period things appear to have changed considerably with regards to electronics etc. It’s such a shame to see that some of my favourite manufacturers like Model Slipway and Electronize have disappeared. I will probably order from Howe’s Models. Going back to the battery do you think the type in the photo below would be suitable? I had a couple of these in my beautiful Aerokits Fire Tender 48” that I foolishly sold.

Morning Sidestick.
It’s a pleasure.
My choice would be the Mtroniks Viper Marine 15 “Brushed” for your motor.
These are readily available from most outlets.
They are advertised in Model Boat Magazine if you take it and lots of on line suppliers such as Howes Models of Kidlington.Cornwall Model Boats.Ebay(although don’t buy second hand) Model Boat bits etc or of course from your local model shop if you still have one near where you live.
Please remember this is my personal choice and there are many other excellent products out there.
Regards Bill

A fine looking boat with a new lease on life .Great find.
Rick

Thanks Scratchbuilder. This is just the kind of advice I’m looking for!

The model is so beautiful and obviously built with such love and devotion that I don’t want to do anything to it that I don’t need to in honour of its builder 60 years ago.

What would be your absolute choice of ESC? Manufacturer/model number?

Thanks in anticipation 👍

Hi Smiffy. Thanks for your comments. I might actually do a little walk round video and put it on YouTube for all to see. I’ve recently found out about the plan and that you can also buy a semi-kit with the plan and some pre-cut wood parts. I’ll keep posting as I’m going along. Thanks again.👍

Hi Sidestick.
Looks like a nice little project.
Personally I would stay with the original motor if it is in good order.
It sounds as if you havn’t done a test as yet,so my advice would be disconnect motor from the prop shaft (this will reduce the load on the motor) particularly if the shaft is a bit rusted or old oil clogged.
Without running for some time the motor bearings will probably be dry so if possible a very small amount of very light oil on the bearings and rotate first by hand to let it run around the motor shaft.(literally a wipe over with a cotton bud soaked in oil will be good.
Then try the motor on a 3 volt run and let it gently settle itself.
If your happy then after a 15 min run up the power and see how it performs.
Gently gently is the answer.
I do suggest that you remove the prop shaft and clean the tube and shaft and pack with light oil or waterproof grease(plenty out there on the market)
Pop it all back together and re run it in.
If the motor does not work then go to plan B,ie new motor.
Re the battery a good Nimh will be fine.
There are many speed controllers on the market.
I like the Mtroniks,but have many other types.The Viper would be more than man enough I would have thought.

Most important thing with this is,as it’s not run for a long time treat her gently to save damage.
Good luck.
Keep us posted.
Regards Bill
Ps.I am always happy to stand corrected.

Very interested to see this boat mentioned as it is one that I began building in the 1960's (until A levels intervened). I had intended to fit it with the water-cooled Allen-Mercury AM35 diesel that I had at the time but although the hull was done the engine was never installed - one of those many unfinished projects which I still seem to accumulate!🤔 The plan, MM530, is still available from Sarik Hobbies if anyone is interested in making a start as it is a nice little boat! I found Vic Smeed's designs were always great to build and I did actually finish his E boat (then sold it to a friend!).

Thanks Jarvo. I was thinking along the lines of a sealed lead acid battery for a longer run time and ballast.
Can you recommend a speed controller? Thanks👍

As a restoration, i would go with the original motor (subject to test) fitted with a speed controller possibly Nimh batteries, but could go with Lipo's. Failing the motor test, put a call out on the forum, bet a member has one in their stash