Air Intake Shut Off

Mark Anderson · 21 October 2004, 12:32

Anybody got any advice on how best to provide a way of shutting off the air intakes on the engine box, so as to comply with MCA coding regulations regarding fire fighting.

The intakes are on each side of the engine box lid and are S/S vents approx. 1.5m long x 80mm high.

Nick Hearne · 21 October 2004, 12:51

Gaffa Tape!

Pete7 · 21 October 2004, 13:04

Mark, made up a pair of marine ply blanks for mine, which the surveyor did check to ensure they fitted. Sure you could do something similar creating a shallow box that fits over the vent and held in place with a couple of catches or bolts. It doesn't have to look pretty cos the customers aren't going to see it and if they do then cosmetics are going to be the least of your concerns.

Pete

codprawn · 21 October 2004, 14:50

Quote:

Originally Posted by Mark Anderson

Anybody got any advice on how best to provide a way of shutting off the air intakes on the engine box, so as to comply with MCA coding regulations regarding fire fighting.

The intakes are on each side of the engine box lid and are S/S vents approx. 1.5m long x 80mm high.

Not seeing exact arrangement hard to say but would it be possible to mount some rails so a strip could be slid in from the end?

Mark Anderson · 21 October 2004, 15:06

The slide in plates were something I had considered but I would need to run that past a surveyor to see if the speed of finding them and inserting them might be an issue. Mind you he was pretty non-comittal with the last question I asked him.

Something similar would be a S/S plate on a piano hinge with neoprene gaskets.

The only other option I have heard of is fire proofed hypalon flaps with velcro.

None of the solutions I have heard or thought of so far are particularly elegant, but I will keep looking

What would have been really nice would have been if Ribtec had sorted it when the boat was built !

Searider · 22 October 2004, 08:37

Hi Mark,

A stainless steel flap on a piano hinge would be one of the best solutions - its always there and can't be lost.

The flap does not have to be on the outside of the box - can you fit them on the inside and operate them with cables?

Jono Garton · 22 October 2004, 09:46

Quote:

Originally Posted by Mark Anderson

Anybody got any advice on how best to provide a way of shutting off the air intakes on the engine box, so as to comply with MCA coding regulations regarding fire fighting.

Is this needed for engine box's? i may be wrong but i was told only for engine rooms?

Mark Anderson · 22 October 2004, 10:14

Yellow code of practice for vessels under 12 metres

"14.1.2.3 - An engine space should be arranged that, in the event of a fire, the fire extinguishing medium injected can be retained for sufficient time to extinguish fire"

This is the part of the code that requires some form of vent closure, and it applies to any inboard engine installation.

Pete7 · 22 October 2004, 12:31

Quote:

Originally Posted by Jono Garton

Is this needed for engine box's? i may be wrong but i was told only for engine rooms?

Jono, what was the arrangement on the Prosport with the D6 ?

Pete

DGR · 22 October 2004, 14:09

My Ribcraft is built to a 'commercial spec' - but it doesn't have sealing vents. It does have an auto extinguisher. If the coding quote says

"14.1.2.3 - An engine space should be arranged that, in the event of a fire, the fire extinguishing medium injected can be retained for sufficient time to extinguish fire"

Then surely you can put the fire out by flooding the whole place with as much agent as possible, for as long as possible. Completely sealing the vents would be a real pain in the ****.

It also doesn't specifically say that you need to seal the vents.

Dylan...

Jono Garton · 22 October 2004, 14:44

Quote:

Originally Posted by Pete7

Jono, what was the arrangement on the Prosport with the D6 ?

Pete

D3 - auto fire extuinsher

I havent seen a coded open boat with vent that shut off. I seem to remember the surveyor mentioning somthing about engine rooms.

quinquarimarine · 22 October 2004, 20:46

On an inboard there must be a vent flap or other device to close air intake.

Common solution is a metal box intake with a flap of metal than can be closed by say pulling of a pin. This will be preferred option or even better would be a remote via a morse cable. Alternatively a "glove" may be placed over the intake on a protruding pipe intake.

All very easy to sort - a quick engineering solution I would say less than £100.

Cheers

John

Paul Glatzel · 22 October 2004, 20:52

Quote:

"14.1.2.3 - An engine space should be arranged that, in the event of a fire, the fire extinguishing medium injected can be retained for sufficient time to extinguish fire"

This is the part of the code that requires some form of vent closure, and it applies to any inboard engine installation.

Mark

This doesn't actually state the need for a vent closure althougth i would agree that it might be a reasonable interpretation. I wonder whether you might consider whether the surveyor is ideally matched to your type of craft. I know of some that take such a literal interpretation of the rules it is surprising they ever pass a boat whilst others take a far more realistic approach and assess each boat on its merits. I know of diesel ribs that happily passed coding without such vents having a shut off mechanism.

Paul

quinquarimarine · 24 October 2004, 23:20

I agree with Paul that a pragmatic surveyor will interpret relevant to vessel as found.

You may though find that many surveyors are well experienced deep sea masters or chief engineers and will value the use of a simple mechanical system to slow down and eventualy stop fire.

The fact is that the surveyor has, on sight of the vessel, put this forward as his prefered option. Putting to the surveyor the paragraphs of the coding may not be the best solution when a simple engineering solution is available. ie. curse, groan, do it and smile !!

If I remember rightly (and happy to be stood corrected) the fire flaps are a requirement under SOLAS chapter 111 and the harmonised codes require any RIB over 8m to be built to a standard of SOLAS chapter 111. Thus a big can of worms can be opened here.

Cheers
John
www.quinquari.co.uk

Mark Anderson · 25 October 2004, 08:56

Thanks for all the replies.

I think a remote operated flap or sliding plate is the way forward, something to keep me busy over the winter.

Dont you wish legislation was more black and white and required less interpretation !

Pete7 · 25 October 2004, 09:09

Quote:

Originally Posted by Mark Anderson

Dont you wish legislation was more black and white and required less interpretation !

Like the plain English campaign, or buying a house without the need for a solicitor to guide you through the minefield ? Yes

Agreed, some of the rules say "should" when they actually mean "shall"

Pete

Turbodiesel · 30 October 2004, 20:41

I think we do the item you want off the the shelf, Call 01869 363636 (E.P Barrus Ltd) and ask for Special Products Division. Im pretty sure all the MoD 6 Clyinder Yanmars have this mod done to them for SOLAS approval.

Searider · 31 October 2004, 09:44

Quote:

Originally Posted by Turbodiesel

I think we do the item you want off the the shelf, Call 01869 363636 (E.P Barrus Ltd) and ask for Special Products Division. Im pretty sure all the MoD 6 Clyinder Yanmars have this mod done to them for SOLAS approval.

I think that may be the flap that shuts off the air intake to the turbo in the event of an inversion - as also fitted to Navy P22s?