I did suspect you did not have much experience of narrowboats. right from the start of canal boating becoming popular the engines were either diesel or outboards. The very early enthusiasts used any engine they could get often petrol or TVO engines but they were very few. This means that the dangers of petrol on canal boats never had to be faced as much as it did in the launch sector. The commercial carriers also were very early adopters of diesel propulsion so again there was little or no experience of petrol.
On the other hand lots of launches on the Thames and such like had petrol engines and they did literally blow up on occasions caused by the fumes from fuel leaks or during filling. This made it prudent to fit bilge blowers. As far as I can tell its the insurance companies, good practise, or Loyyds who insist on bilge blowers on non-inland craft. Another aspect is that "all in one" bilges can absolutely reek if they are left to fester for years so the gentleman owner might get a few "nasty niffs" without a bilge blowers. The Boat Safety Scheme and the Thames Launch Regulations before that ensured that the opportunity for LPG leaks was minimised to such an extent that I have never been able to find any data on gas explosions per number of boats. It seems that petrol explosions are more common, often when refuelling outboards from a jerry can. All of this means there really is no pressing need for bilge blowers on any well maintained diesel craft. As far as automatic bilge pumps are concerned. They were probably vital on wooden boats that might starts to leak at any time, but I suspect only a fool would leave a wooden boat unattended for months on end and most people would know how vital keeping the battery charged would be. On a GRP boat boat its cockpit cover up or a more modern steel narrowboat with its self draining cockpits or comparatively small area of exposed non-self draining area the only way water should be able to enter the hull is from rain and rain will take ages to build up sufficiently to cause major problems. An automatic pump gives the owner a feeling of safety if they do not visit the boat regularly - until the battery fails. Once the battery or pump has failed is when problems occur. Either you give a false sense of security and an excuse not to visit the boat to the owner or you give them every excuse to visit the boat on the pain of expense. I knows which one I would choose! I know a swinging mooring can expose boats to wave action, but not on inland boats which might make an automatic pump prudent.. Remember modern narrowboats tend (with a few exceptions)to have a totally separate cabin bilge with perhaps 3 of 4 inches of clearance between the base plate and cabin sole (mine has close to 6 inches) and the cabin sole is on-removable so dirt etc can not find its way into the bilge. Unlike certain sailing yachts that have zero to about 2" of gap with the 2" gap only being right in the centre of the cabin. (that 3 or 4 inches does have things like paving slabs in though. Even a rear bilge flooded to 18" would not put a narrowboat into significant danger because its only the back 5 ft or so and it tapers. As soon as the owner goes aboard they would automatically pump it out. Then there is the oil/fuel pollution issue related to automatic bilge pumping in the engine area which is far less of a problem on tidal waters. Its up to the individual which is why I said "personally" but I see little advantage in using an automatic bilge pump. However I know loads who do. Tony Brooks --- In [email protected], Trevor <listsandst...@...> wrote: > > Thanks, Tony, > > Perhaps I should mention that I didn't expect a bilge pump to remove LPG > <g>. > > Regarding bilge blowers, we either had small cowl vents fitted or used > powered blowers, fitted at deck level and ducted down, to ensure a good > draught through the bilge. > > I was a little surprised by your comment about automatic bilge pumps > though - although I must bow to your obvious experience with NBs (and to > my equally obvious lack of it <g>) - as I've never worked in a boat > without one, albeit my own experience in small craft has been coastal > with its rather different requirements and, usually, 'off-shore' moorings. > > Cheers :-) > > Trevor > > Tony Brooks wrote: > > Never seen one yet and even if one was fitted I am not convinced the motors > > are sealed against gas. I have seen no mention of bilge blowers in > > connection with gas on the BSS website. Bilge pumps are extremely unlikely > > to pump gas and I would guess never will. > > > > Personally I would never fit an automatic bilge pump. The accommodation > > bilge should not have a significant amount of water in it, if any at all > > and the engine bilge should only have rain water in it. However I, > > personally, do not subscribe to the stern-gland must drip argument so all > > mine has to deal with is rain and as long as you visit fairly regularly it > > never gets above the engine beds. I do take great care in exactly how I > > adjust the stern-gland and I do have an Aquadrive which helps minimise > > packing wear. > > > > > [Non-text portions of this message have been removed] >
