Submarine Exhaust system [diesels]

[ivorthediver]

Can anyone tell me how the exhaust systems were sealed from seawater entry when diving

I realise that the diesels were shut down and propulsion was supplied by the Electric motors ,...but at some point these would have to be sealed to prevent sea water entering the engines surely ?

[Paddy]

Can anyone tell me how the exhaust systems were sealed from seawater entry when diving

I realise that the diesels were shut down and propulsion was supplied by the Electric motors ,...but at some point these would have to be sealed to prevent sea water entering the engines surely ?

I was not a submariner Ivor but I should immagine a combination of non return valve innitially followed by a b....y great stop cock.

Paddy

[ivorthediver]

Sounds about right ,but I wouldn't like to go down if it were only a bung

[Scratcher]

Well Ivorthediver,very soon you will know all the secrets of the Underwater Navy.If you were stood in the Engine Rm on the Second Blast of the Klaxon(Patrol Routine)the submarine was already opened up for diving,you would see two Stoker's move like greased lighting to get to Two Large Valve handwheels,situated midway down the engines and above them,they were called the Muffler Vvs these had to be shut as the Donk stopped as sea water was kept out of the engine by exhaust pressure.All classes of Diesel S/Ms were basically the same.

[CGRET]

Ivor,

Here is a simple illustration on how it functions.


35513


Again very simple.

Regards
Charles

[ivorthediver]

Thank you Charles ,

I have often wondered how it worked and conjured up all sorts of explanations.


Again my thanks....and the picture ...always better than an explanation

Kind Regards Ivor

[CGRET]

Ivor,

Not a problem.

Regards
Charles

[Macadian]

Ivor,

Here is a simple illustration on how it functions.


35513


Again very simple.

Regards
Charles

Not being a Submariner (was always General Service) I hope the following does not sound too silly. On the boat surfacing and going onto diesels, did the exhaust gas build up on the engines being started force any sea water lying in the exhaust trunking on the sea side of the isolating valve purge the exhaust line of water? Just a thought.

[CGRET]

Macadian,

From the reference material I Have the salt water in the pipe aft of the isloation valve was alway's settling in the pipe or muffler. But once the engines were started on the surface, there was water cooling added to the exhaust, moreover it helped in muffiling the exhaust noise produced by the engines. So yes a certain amount of water did in fact settle in the pumping aft of the isolation valve.

Hope that answers the question.

Regards
Charles

[Macadian]

Macadian,

From the reference material I Have the salt water in the pipe aft of the isloation valve was alway's settling in the pipe or muffler. But once the engines were started on the surface, there was water cooling added to the exhaust, moreover it helped in muffiling the exhaust noise produced by the engines. So yes a certain amount of water did in fact settle in the pumping aft of the isolation valve.

Hope that answers the question.

Regards
Charles

Much as I thought...thank you.

[Odin]

The valves don't always work correctly - the RN have experienced problems in this area in relatively modern times.

Not wishing to go in to details I did find this on another site refering to the Upholder Class (now with the Canadians) which possibly relates to the problem seen with this class during acceptance trials:

With the Unseen [renamed HMCS Victoria] sailing under RCN Command, defects were found in her exhaust valves which put the Victoria out of action for a year domiciled in Halifax harbour

[CGRET]

Odin,

You are correct, they did not always operate as planned or as designed.

Regards
Charles

[Paddy]

Odin,

You are correct, they did not always operate as planned or as designed.

Regards
Charles

Was the engine cooling via cooling pipes inside the casing ?.
On narrow boats I used ten foot skin tanks wealded to the inside of the hull and cooled by the outside water, but for engines of large capacity I don't suppose that would be sufficient,

Paddy.

[CGRET]

Paddy,

Most of the time it salt water cooling the engine. At various point's on the marine diesel there are zinc's. These zinc'z are there to protect in the inner water cooling jacket's on the engine. Thus the sea water in pumped into the engine via the sea chest with a sea strainer. Once pumped through the engine the water is discharged through the exhaust system overboard muffiling the exhaust.

Hope this helps

Regards
Charles

[Paddy]

Paddy,

Most of the time it salt water cooling the engine. At various point's on the marine diesel there are zinc's. These zinc'z are there to protect in the inner water cooling jacket's on the engine. Thus the sea water in pumped into the engine via the sea chest with a sea strainer. Once pumped through the engine the water is discharged through the exhaust system overboard muffiling the exhaust.

Hope this helps

Regards
Charles

Hi Charles,

I have used raw water cooling but I did not think you could use salt water.
On fresh water boats it is primarily used so that the waste water from the engine can pass through an external jacket on the exhaust manufold to cool it. We also take the incoming water through a mud box, to catch silt and weed, which you would not have had to worry about, more likely to get shrimps.
In that type of system we pass the exhaust gasses through a box with what I can describe as a toilet P trap to stop returning water as the outlet is only an inch or so from the water.
I expect something similar would be incorporated in sub's.

Paddy

[CGRET]

Paddy,

Yes, you can use salt water. That was the reason for the zinc's in the water cooling area's on a marine diesel is for protection. The other cooling system is anti-freeze mix, which has it's own cooling system in the engine. The principle is the same wether it's fresh water or slat, Cooling.

Regards
Charles

[Paddy]

Paddy,

Yes, you can use salt water. That was the reason for the zinc's in the water cooling area's on a marine diesel is for protection. The other cooling system is anti-freeze mix, which has it's own cooling system in the engine. The principle is the same wether it's fresh water or slat, Cooling.

Regards
Charles

I belive the main difference between engines that can take raw water cooling as oposed to closed circuit, is the size of the internal water passages.

Some diesel automotive engines such as British Leyland and Thorneycroft can be used in boats with raw water but most can only use the latter. all marine engines have large water passages.

I have seen stripped down sub engines ( very old ones ) and you would not call the cooling system, water passages, they look as if the cylinders are suspended in a bath, hense, no restrictions for blockages.

Paddy

[Rorqual]

My MFV engine is a salt water cooled diesel .
Salt water provided from a sea cock [two of them -in case of strainer getting
choked in one ] water flow to the 'pots 'and heads and out via the exhaust manifold with the exhaust gases .
circulating water pump speed controlled by engine speed.
The cylinders are whats called 'loose liners ' in the water jackets.

The exhaust pipe is a heavy rubber hose to outboard.

My previous MFV had a Leyland and it had a coil system in the bilge aswell as a conventional radiator set up for cooling the engine -enclosed system fresh water with anti freeze.Dry exhaust .