M1

[Paul TParticipant @pault84577]

Hi Grumpy

My apologies as I had completely missed your last post (I used the "go to first unread post" shortcut and it jumped over yours) although my current meds put me on another planet sometimes and at those times I could miss the end of the world.

I would be very grateful for anything that you could e mail to me and I shall send you my address through a pm.

Thank you very much for your interest and help with my little project.

All the best

Paul

[Paul TParticipant @pault84577]

Thanks where it is due. 

Very very many thanks to Grumpy who has provided me with a huge ammount of information on the M and K class boats, all by e mail and all on BMP format (which is perfect for CAD) it must have taken him ages to scan and convert all of the documents.

Once again a HUGE thanks to Grumpy

Paul

[RichieParticipant @richie]

Hi Paul,

Just out interest, but which CAD program are you using to convert BMP format files?

Cheers

Richie

[Paul TParticipant @pault84577]

Hi Richie

The best CAD programme that I have found for importing photos so that I can copy them is TurboCad the import of BMP files is smooth and has no loss of detail even under large magnification.

I have used other CAD systems in the past such as AutoCad but have found them limited in function for my method of working.

I find that with TurboCad there is no loss of detail by programme or format stretch, when I work I electronically trace the original drawings and then check back to the paper or download version to verify the dimentions.

It might sound like a long winded way to produce a set of scale working drawings but it enables me to become fully familiar with the subject.

Paul

[RichieParticipant @richie]

Hi Paul,

Thanks for the information. I have AutoCad but cannot find function to import BMP. I think i had an old copy of TurboCad – I will see if i can dig it out and give it a try.

Richie

[Paul TParticipant @pault84577]

Hi Richie

Here is an example of an extract of the M1 drawings I am working on at the moment.

This image has been in and out of TurboCad without any problems.

Paul

[RichieParticipant @richie]

Hi Paul,

  After some digging I can now import my plans into AutoCad, so may well try your ideas.

There is a book on M class Submarines, I have not read it yet so cannot comment on how much information if may be able to give you:

Martin H. Brice M-class Submarines, Outline Publications, 1983, ISBN 0-946784-00-0 

Richie 

[ashley needhamParticipant @ashleyneedham69188]

There is a very nice cutaway model of an m1, the centre section showing the gun etc etc  in the Science Museum in London. I took a piccy at 8Mp but have given up trying to resize it on my computer. Could e-mail if interested. Ashley

[Paul TParticipant @pault84577]

Hi Ashley

Is this the one?

You would not believe how much information on the M class boats that I have aquired over the past few days.

Many thanks for your offer of help.

Cheers

Paul

[ashley needhamParticipant @ashleyneedham69188]

Paul, gosh, looks very similar !   Ashley

[Paul TParticipant @pault84577]

Hi everybody

A technical question for the model submariners.

Can anyone help me with the problem of pumping out the ballast tanks when the model sub is under water …….how do you compress and store the air? and how do you blow the tanks and maintain trim?

Paul

[ashley needhamParticipant @ashleyneedham69188]

Paul, following on from the other thread, you have a nice set of drawings in TurboCad (whatever that is), it seems to me that printing them out of thin card would be easy and give you "instant interior detail " to view through hatches or something. You could then apply this to any boat interior.. in fact it would be a great way of enhancing a boat, without going to great lengths on interior stuff that a) hardly anyone will look at b) is difficult to see anyway, and therefore wasted if you have spent a long time over it. .  Ashley

[Paul TParticipant @pault84577]

Hi Ashley

Nice idea and it would be very easy to do with the cad programme but the M1 model is to be a fully diving example and so there won’t be any interior to see.

Paul

Tenor or Alto?

[ashley needhamParticipant @ashleyneedham69188]

Alto, but i have a full set for versatility

How are you going to make the big gun fire?? Ashley

[Paul TParticipant @pault84577]

Good morning Ashley

As my old band mates used to say "the joy of sax" the alto gives a very nice sound, I tried to play but could not get used to the mouthpiece.

Getting the gun to fire would not be a problem but keeping the water out of it would be even the real M1 had problems with water getting into the barrel as during one firing the gun blew apart.

But these problems are sent to try us and keep us awake at night.

Paul

[ashley needhamParticipant @ashleyneedham69188]

How about, as an idea, actually USING the water in the barrel to make a firing effect? For instance, if you had a one of thoses small Co2 bottles in the sub, then this could be used to give a puff down the barrel and eject a burst of water to look like its firing, conceivably you could get loads of shots out of one bottle (after all these things are used in Co2 air pistols)….hang on.. you could use the mechanism of one of those pistols for the works? you could experiment with different barrel bores to get the best result, and of course it would be self loading!     Ashley

[Paul TParticipant @pault84577]

Hi Ashley 

Nice idea but I want to have the gun belching smoke and flame, I have the pyrotechnics to achieve this but I am still stuck with the problem of how to keep the barrel watertight when underwater.

Any ideas

Paul

[ashley needhamParticipant @ashleyneedham69188]

Paul.  Thin wax disc over the end of the barrel?  or perhaps leaving a small recess at the barrel end to hold a waxed paper/card disc?   or a small circle of clingfilm just around the end. ? electromagnetic flap at base of barrel, operated upon firing…perhaps with a small drain hole at the bottom of the barrel so water is normally IN the barrel, but upon surfacing ready to fire the barrel drains away and …boom! another dukw bites the dust.  Small spring loaded flap at outer end of barrel, this wouldnt have to be a strong spring as water pressure would hold it shut at 300 meters, but when firing it would simply fold / be blown out the way..    compressed air jet to clear the barrel before firing on the surface? waxed end to shell/whatever to prevent water ingress beforehand inboard.    Have the pyrotechnics at the FRONT  end of the barrel, with a waxed end to stop the damp… ummmmm     Roughly how large is the bore on this behemouth scheduled to be?? 1 inch? two?       You could do what the soldiers did on d-day  to stop water getting in thier barrels…supposedly   . A green ribbed tickler might do the trick and match the camouflage.    Ashley

[Paul TParticipant @pault84577]

Hi Ashley

Nice set of ideas I like the notion of the electromagnetic flap or disk at the base of the barrel used in conjunction with a drain hole.

The designed dia of the model barrel is 1 1/2in (32mm) and I intend to use copper pipe as the build material as it won’t rust and can withstand the explosive pressures. 

To continue through your other suggestions I can’t use anything that goes over the end of the barrel as that would require the model to return to shore for re protecting before the next dive and don’t want to use a flap on the end of the barrel because it would be seen.

I shall conduct a few experiments to see if your flap idea will work.

Thanks for the help

Paul

ps what did the men use to keep the guns dry? I have never come across that term before. 

[ashley needhamParticipant @ashleyneedham69188]

Paul. Shotgun cartridges…not that you want to use them, but they are plastic, crimped at the front end and thus waterproof.. A shot that was a snug fit at the base of the barrrel (possibly reduce the breech diameter if required) would plug the hole, and a drain hole in the barrrrel  situated JUST in line with the crimping would drain the barel upon surfacing, but when the cartridge fired, the front end of the crimp would be flattened against the drain hole thus blocking it and not giving extraneous venting other that at the bang end.  I did think of a revolver sort of idea, sprung loaded to push against the botom of the barell to make a seal, shots could be loaded automatically then, and used in conjunction with a drain hole. Even if you used just one shot instead of a whole 6 pack, this would seal the breach, then present a round for firing.??   Ashley

[ashley needhamParticipant @ashleyneedham69188]

Thinking about it, would you need a drain hole, as the gun attitude in its crade appears to be to be downwards, draining any water straight away on surfacing. Its going to be difficult getting the rifling done in copper..

How are you going to make the working torpedoes to go with the working gun ??????? 

Have you not heard the urban myth that Churchill wanted a well known manufacturer if such items to make them for the purpose of water exclusion, in their largest size , but to mark them "extra small"   ?Ashley

[Paul TParticipant @pault84577]

Morning Ashley

Thanks again for your comments. I have had a play with the various suggestions and come up with a working solution, which is as follows:

When not in use the barrel will rest in a level position and so will drain 90% of it water as the boat surfaces and the rest of the water will drain through a small hole at the base of the barrel.

To keep the water out of the charges I will use a 1/2 in gas valve at the end of the barrel (just like a washing machine tap) which will operated by a servo, the same servo will also elevate the barrel into the firing position the raising of which will ensure that any remaining water in the barrel is sent to the drain hole.

Once fired the operating servo will close the valve and lower the barrel to its rest position before the boat submerges again.

With this process I can surface the boat and fire the gun as often as I like without having to bring the boat to the shore for re loading.

Thanks again

Paul

[Paul TParticipant @pault84577]

The sub with the big gun

[Author]

Posts