M1 Submarine

[Mike CaswellParticipant @mikecaswell26782]

A page for the M1 submarine 

[Paul TParticipant @pault84577]

Hi Mike

Thanks for the photo of the M2 this boat originally had a cannon just like the M1 but was converted to carry a small aircraft. The plane was carried in the hanger at the front of the conning tower, the bit that looks like a gun barrel is the recovery crane.

This boat also sank when the hanger door failed during a dive.

The remaining boat of the M class became a mine layer and gave excellent service.

Paul

[Paul TParticipant @pault84577]

Hi Ashley

Thanks for the tip about MM I shall get a copy today

Paul

[Mike CaswellParticipant @mikecaswell26782]

and here is the M1 with gun

Here is the M2 with plane

I have a source for a 1:72 scale static diving model, if anyone is interested.

and here is the M1 with gun

Here is the M2 with plane

[Paul TParticipant @pault84577]

Hi Mike

Thanks, the photo of the M2 is one that I haven’t seen before but your M1 photos did not come through.

Yes I am interested in the static diving model.

Paul

[Mike CaswellParticipant @mikecaswell26782]

Paul

The M1 is the picture with the big gun, the M2 is with the plane.

Can you PM me on this board?

[Paul TParticipant @pault84577]

Mike

Sorry but I cant pm you until you enable the pm facility on your profile page.

Paul

[Mike CaswellParticipant @mikecaswell26782]

Paul

I think I unlocked the pm thing

[Paul TParticipant @pault84577]

Good Morning Mike

Thanks for the pm and thanks again for the photos although the M1 photo hasn’t come through so could you please re-post the M1 photo.

Paul

[JC Uknz 1Participant @jcuknz1]

Six members of the Boat group of Otago Model Engineering Society [NZ] scratch-built themselves a nuke sub each as a group project.  I am not one of them but I gather the boats are balanced so they need very little air being removed/ stored and are capable of diving/surfacing without moving horizontally. 

The air is compressed into the electronic control area to dive and then released, returning to the flooded compartment to surface.     Powered by 12v 7.2Ah batteries I was suprised to learn that the batteries are in the flooded compartment and don’t ‘short’ as I would have expected when under water.

It is slightly nerve-racking operating a surface boat in the neighbourhood becuase the fine wire aerial is hard to see and one doesn’t want to hit another member’s craft.   Part of the sub captains fun is to move underwater and fool the rest of us   Their only drawback is their large turning circle. Currently amongst the bigger craft in the club.

Very popular with visitors on open days.

[JC Uknz 1Participant @jcuknz1]

One of the OMES nukes …..

[Mike CaswellParticipant @mikecaswell26782]

There are many ways of controlling the ballast tanks in a static diving submarine, and I have a document explaining this at:-

The Pro’s & Con’s of Ballast Systems

I also have some videos on youtube.com

The Skipjack is a larger submarine, but has a phenominal turning circle.

There is also a movie of the Trumpeter Kilo.

[Paul TParticipant @pault84577]

How do you make it dive & surface

[SubwarrierParticipant @subwarrier]

Hi, Can I attempt to answer the question about the tube dive system.

The middle tank has open vents at the bottom to allow water in and flood the tank when the ballast pump is operated, the air is stored in the fore and aft tanks where all the electronics are kept (hopefully) dry under pressure. more water coming in = the heaver the sub gets and she will eventually dive. to surface a valve is opened allowing the pressurised air to push the water back out of the tank and lighten the sub until she (hopefully) surfaces again.

Going down is easy, coming back up is the difficult bit, staying at a nice level periscope depth is even harder and some even cheat by fitting automatic levellers to the dive vanes.

To complicate things there are many different ways to take onboard ballast, Engels tanks (big syringes driven by a motor), Eden system (pumping water into a sealed tank pressurising the air above it), Craycraft system (pumping the air out of the tank into the rest of the tube), Darnell system (using a small steam engine pump to cycle air in and out of a balloon).

Many ways to do it but they all involve shifting the weight of the ballast.

Regards

S

Edited By Subwarrier on 07/09/2009 17:28:38

[ashley needhamParticipant @ashleyneedham69188]

Paul. And how is the leviathan of the seas progressing?? or is it still in the design stage.

 

That Steve knows a thing or two, his humungous Ohio has a Captain in the conning tower that goes up and down when diving/surfacing  !!  (well impressed)

 

Ashley

[Paul TParticipant @pault84577]

Hi Subwarrier / Ashley

 

Thanks for the info, the boat is still at the design stage as I am having problems with the design being top heavy and difficult to trim, the design programme is asking for more keel level ballast but this makes the boat to heavy.

I will get there in the end.

 

Paul

 

 

[Yabbie1Participant @yabbie1]

Hi Paul,

 

I would add a couple of points relevant to the design process:

 

The size of ballast tank required is equal to the displacement (not weight) of the total above-surface hull/superstructure when the model is in surface trim.  The M1 has a large superstructure due to the turret etc. so will require a large tank.  To minimise its size, the superstructure needs to be completely free-flooding and as thin as practical.  Reducing the thickness of the material used in the free-flooding superstruture from say 3mm to 1.5mm will halve the size of ballast tank required.

 

The location of the ballast tank must be such that its centre of gravity is on a vertical line that passes through the centre of buoyancy of the total above-surface structure.  This is usually around the centre of the hull length, but the turret will cause it to migrate a litte forwards.  Small errors in location can be compensated for during the trimming process with small blocks of foam and lead.

 

If the model is looking overweight, consider a higher-density battery (NiMH instead of SLA), brushless motor(s), minimising free-flooding areas below the surface waterline to increase buoyancy (eg total dry hull), smaller servos etc.  Mount parts as low as possible obviously to minimise the fixed ballast requirement.  For example, mount motors under their gearboxes, not over.

 

On your side are the M1’s twin props, which mean you can get away with a reduced metacentric height (static stability) as counter-rotation will mean you won’t have to fight the torque reaction of a single large propeller.

 

Good luck, just imagine that menacing 12″ gun heaving up out of the murk on sailing day.

 

 

[Paul TParticipant @pault84577]

Hi Yabbie

 

Thank you, this information is just what I was looking for and I will amend the design programme to include your advice.

 

The prospect of the monster heaving up and having the gun fire during a sailing day is nice one but I have a lot of work to do before I get to that happy point.

 

Thanks again for taking the time to give such superb advice.

 

Paul

[Paul TParticipant @pault84577]

Hi Yabbie

 

I have recalculated the model based upon your advice and the simulations look very good but the computer model rolls when starting to dive.

Hence I am still having problems with the model being top heavy (the gun and firing system being the problem) and as I cant get the motors /  batteries etc any lower in the boat I am now trying to reposition the firing system from the turret to a location deeper into the boat but this means redesigning the firing system to enable it to work by remote.

 

At least with your help I have been able to reduce my problems down to one item.

 

Thanks again

 

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

 

Why not mount the battery etc in a box slung underneath?

 

More stability….More space inside!

 

 

 

Just passing……………….Bob

[Paul TParticipant @pault84577]

Morning Bob

 

I want to keep the model true to scale so I can’t use a underslung weight or extended keel (I had thought of a slightly extended lead keel but it didnt look right)

 

Its fun going through the design process and seeing the problems that the RN architects had when they designed the real M1 and they didnt have the luxury of computers so it must have been a nightmare.

 

Paul

[Yabbie1Participant @yabbie1]

Paul,

 

I am curious to know what software you are using for your similations, and also what scale you are thinking of for the model.

[Colin BishopModerator @colinbishop34627]

Paul,

 

Could it be that you are up against the laws of physics here? Yabbie1 in his earlier posts has stressed the need to reduce the thickness of the hull material as much as possible but you will never get it down to scale size on the model as it would be too thin to have any strength. So you are labouring under an inbuilt handicap with little opportunity to compensate elsewhere.

 

This happens in surface models as well of course but in your choice of prototype it is probably more critical.

 

Good luck anyway, it’s very interesting to hear how you are getting on.

 

Colin

Edited By Colin Bishop on 26/09/2009 10:25:24

Edited By Colin Bishop on 26/09/2009 15:45:40

[Paul TParticipant @pault84577]

To answer a few questions.

 

The model, should I ever get around to building it, will be approx 8ft long and will split into 3 sections for storage and transport.

The forward and stern 2ft sections would be hollow and free flooding, the 4ft centre section where all the gubbins would be is the part that is giving me problems.

 

Colin: The physics of the materials is not such a problem (given the size of the model) as I could use aluminium for the frame and hull and either glue, rivet or mig weld the parts together.

 

Yabbie: The design software is an altered CAD system into which I have imported a ship design package, I had to write some software to make it work so its a little slow but its ok for my needs.

 

Paul

[Yabbie1Participant @yabbie1]

Paul, I realise you are wisely designing the model for least weight and ease of transport, but you could afford to “reclaim” a little of the free-flooding volume by providing (say) a sealed cylinder along the inside of the nose and tail sections, just below the surface waterlline.  Then invest this buoyancy gain in supporting the weight of the gun mechanism and offset the rest with extra fixed lead ballast along the keel.  You’ll have the extra buoyancy needed to carry the weight, improved stabilty (centre of buoyancy has moved up, centre of gravity down) at the cost of a slightly less weildy model.  Perhaps 0.5-1 litre extra displacement in the nose and tail and 1-2kg overall weight gain.  

[Author]

Posts