Big Metal Cylinder?

[Cheesey69]

Boat built in 1974. 
At the back of the boat above the prop tunnel I’ve got this large metal cylinder with about 12 bolts around it. 
It’s got a reinforced clear pipe going into it and I think it’s my bilge pump but I’ve never seen the like before. 
no photos I’m afraid but is this common?

[Turnoar]

Inspection chamber?

[CambridgeCabby]

Flux capacitor ?

[Cheesey69]

Hole to Chuck money 

[Smoggy]

Photo pretty much critical or we'll keep giving stupid answers, could be anything, my money is a cryo chamber to preserve to contents of the holding tank till it can be cured and live a long and healthy life and work as a shelf stacker in tescos....

[CambridgeCabby]

Agreed , to be serious , if you upload a photo I’m sure your mystery will be answered correctly 

[OldBerkshireBoy]

Access chamber to the prop? Mine is around 18" diameter but grp.

[NeilB]

What boat is it?  A lot of Bounty’s and some Alphacraft had weed hatches, don’t think I’ve seen one on an Aquafibre.

it would be in front of the rudder stock and hopefully the top will be a couple of inches above the waterline!

 

[YnysMon]

1 hour ago, Cheesey69 said:

Hole to Chuck money 

Actually, I was in two minds whether to react to this with the laugh icon or the ‘oh err’ (sad) one. 

[Mouldy]

7 hours ago, Cheesey69 said:

Hole to Chuck money 

That wouldn’t be big enough . . . . . . . . . . . . . . . . . think more like the size of hole that your hull makes in the water!!😉

[JanetAnne]

Just a thought

https://www.ebay.co.uk/itm/5-Litre-Accumulator-Tank-Safe-For-Drinking-Water-Narrowboat-Caravan-Motorhome/282805702165?hash=item41d8888e15:g:fhwAAOSwD2Ncnf92&redirect=mobile

[JanetAnne]

[grendel]

oil trap for outlet, or water chamber for exhaust to muffle it more

[BroadAmbition]

Sigh,

it’s obviously a Scrinsen Doodah
 

All boats have at least one in one form or another 

Griff

[Cheesey69]

1 hour ago, BroadAmbition said:

Sigh,

it’s obviously a Scrinsen Doodah
 

All boats have at least one in one form or another 

Griff

I thought I saw BA on Barton Broad this morning, mud anchored . Either way the boat looked magnificent 

[BroadAmbition]

Not us. We’re at Langley Dyke just about to sail for Norwich 

Griff

 

[Cheesey69]

Ok here it is

[Smoggy]

Looks like prop access to me for clearance.

[OldBerkshireBoy]

Looks the same as mine, been told it is access above the prop but will need arms 4ft long to remove anything.

[Smoggy]

4 minutes ago, OldBerkshireBoy said:

Looks the same as mine, been told it is access above the prop but will need arms 4ft long to remove anything.

Or a hooked Stanley blade on a long stick.

[OldBerkshireBoy]

3 minutes ago, Smoggy said:

Or a hooked Stanley blade on a long stick.

Have a Samurai sword I could use if need be.