Why aren't diesel tanks supplied with large inspection hatches for thorough cleaning?

[parbuckle]

I fitted a diesel 150mm version of this http://baileymarine.co.uk/categories/watertight_deckplates/products/bm85_white.html heavy and beautifully engineered in acetol the centre unscrews with a large removable key so access takes seconds I believe the RNLI have used this type on water tanks but this company is the proverbial RR of marine fittings so cost is a big factor well north of £100.

 

[zzyyxx]

I just want a diesel proof mastic.

http://www.hytekgb.com/loc5220-pg-loc-5220

 

[Deleted member 36384]

…. hatches rectangular and not round for IMHO ease of fitting.

Round lids cannot fall into the holes they cover, a primary reason for round lids on tanks.

 

[jwilson]

So if I was looking at a yacht without a good-sized, well-constructed access hatch in the fuel tank, I'd wonder what other cost-corners had likewise been cut in her specification.

OK - you've ruled out about 95%+ of new boats then..... hope you have a healthy bank balance.

 

[Greenheart]

OK - you've ruled out about 95%+ of new boats then..... hope you have a healthy bank balance.

Quite the opposite...but that's what prompted my original question. Even if only once in forty years of use, a diesel tank needs complete emptying, cleaning and decontaminating, won't it be a significantly less expensive job to sort out if the builder had the foresight to fit a big hatch?

If it's accepted that some problematic fuel issues are eventually more probable than possible, mightn't original fitting of access hatches be a good mark of a quality yard? Presumably they're not often found on 'Poundshop' AWBs.

 

[prv]

Even if only once in forty years of use, a diesel tank needs complete emptying, cleaning and decontaminating, won't it be a significantly less expensive job to sort out if the builder had the foresight to fit a big hatch?

Of course it will - but the builder isn't the one who has to do that job.

Pete

 

[Tranona]

Quite the opposite...but that's what prompted my original question. Even if only once in forty years of use, a diesel tank needs complete emptying, cleaning and decontaminating, won't it be a significantly less expensive job to sort out if the builder had the foresight to fit a big hatch?

If it's accepted that some problematic fuel issues are eventually more probable than possible, mightn't original fitting of access hatches be a good mark of a quality yard? Presumably they're not often found on 'Poundshop' AWBs.

Point is - there is nothing new about lack of inspection hatches, or indeed poorly constructed and inaccessible tanks. Try getting the fuel tank out of older boats, or even having access to the tank to get at a hatch if one were fitted.

Such things are low priority for designers and builders - even in so called quality boats. The moulded in GRP tank in the keel (on top of encapsulated ballast) in an HR 35 would be a good example of how not to do things. Or ever tried to get access to the (mild steel) tank on a centre cockpit Moody.

At least in my cheap and cheerful Bavaria tanks (and engines) are very accessible and can be removed without dismantling any furniture.

 

[Greenheart]

Fair enough Mr T, apologies for my AWB jibe.

As you know, I don't presently have a diesel tank or a diesel engine, or a boat that would benefit from either. And I can see that historically, at the dates when thousands of existing boats were built, diesel bug mightn't have been the issue it may be today (unless its profile has only really been raised by social media).

But if indeed builders of yachts of all qualities are consciously overlooking the rather indefinite necessity to access the inside of fuel tanks, for the sake of a few quid, it reminds me of many aspects of design which I've questioned in the past, and which I've repeatedly been told are the way they are, because it's what the buyers want...

...it seems to me much more like a shortcut the manufacturers can get away with because most new boat-buyers' attention will be elsewhere, and as Pete said above, the builders are unlikely ever to be faced with solving any resultant problem themselves.

 

[Tranona]

No different from any other consumer product. Manufacturers respond to customer needs and they make their decisions based on what they perceive customers value. Bavaria's biggest single customer group is charter operators so simplicity and ease of servicing are high on their list of priorities - same for other volume producers. If tank cleaning was a big issue with such operators then pretty sure manufacturers would respond.

Different user groups have different expectations (and depths of pockets) so different features take priority. The tanks I have had made (water and holding) all have inspection hatches because the additional cost on a one off tank is minimal in relation to the overall cost. Never had to use them though!

However, as others have said the cumulative additional cost of the "nice to have" bits on a low cost production boat soon makes it not so low cost.