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Hello I have been looking at grp canal cruisers and I have a question about which engine configuration is best. I have seen two boats for sale same model but one is a diesel shaft drive inboard whilst the other is an outboard. Initially I was drawn towards the inboard engine but then it struck me what do you do about things caught around the propeller. There is no weed hatch on the inboard so how do you clear the propeller when the worst happens and secondly how often does this happen?

Thanks

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As to how often your prop gets fouled is a lottery, depends where you cruise and if Lady Luck is smiling on you. We lived on and extensively cruised our 40' x 12' GRP on shaft boat for 10 years with no problem but that was on the Broads I did get a tarp around my O/B prop though, again on the Broads not a problem though in a dinghy.

Phil

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It is best to avoid OB engines boats if other options are available

 

OB engines will NOT, and Inboard engines WILL

 

1) Charge your domestic batteries.

2) provide Hot water

 

Fuel for inboard engines (diesel) is readily available on the canals and rivers - OB engine fuel (Petrol) is rarely ever found on the canals and you have to trek to the nearest petrol station and carry e fuel back to the boat.

 

Petrol on board boats is dangerous and subject to more severe 'safety checks' than diesel fuelled boats.

 

The legal limit to how much petrol can be carried on board (30 litres I think) is much less than the amount of diesel allowed (I have 2700 litre diesel tank on my boat)

 

There are reasons why an OB powered boat is (around) £5000 cheaper than the same boat with an inboard diesel engine.

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Not sure where you have got that legal limit for carrying petrol on board. Lots of boats we know have large petrol V8 engines and have tanks in the region of 1000 litres or more.

 

Of course storing fuel in containers on board is a different matter.

 

There are several benefits to an inboard diesel over an outboard petrol engine but I wouldn't necessarily rule out the petrol engine. They tend to be cheaper to buy, are cheap and easy to maintain and are quiet.

 

If you are willing to carry fuel to the boat you can get a nice boat for your money.

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Not sure where you have got that legal limit for carrying petrol on board. Lots of boats we know have large petrol V8 engines and have tanks in the region of 1000 litres or more.

 

Of course storing fuel in containers on board is a different matter.

 

 

 

Very few V8 inboard engines are supplied by the 20 litre 'demountable' cans,- I would, however, suggest that the majority of outboard installations are.

 

The legislation is here :

 

http://www.hse.gov.uk/fireandexplosion/petrol-storage-club-association.htm

 

You can store up to 30 litres of petrol at home or at non-workplace premises without informing your local Petroleum Enforcement Authority (PEA).

You can store it in:

  • suitable portable metal or plastic containers
  • one demountable fuel tank
  • a combination of the above as long as no more than 30 litres is kept

For these purposes 'premises' are as defined in the Health and Safety Work Act, etc. 1974 and includes, for example, motor vehicles, boats and aircraft.

 

If you have a 'fixed' (purpose built) installed petrol tank (as in your car, or the 'boat with the V8) then from the Gov. Q&As

Does the petrol in the fuel tank of my car count towards the total I can store?

No – the petrol in the fuel tank of your vehicle, including boats and aircraft, does not count when you are calculating the total amount you are storing.

 

How much petrol can I store on a vehicle?

You can store up to 30 litres of petrol in a maximum of 2 suitable containers in your vehicle. For the purpose of these Regulations a ‘vehicle’ is interpreted as any type of vehicle so includes boats, aircraft and hovercraft. This type of storage counts towards the total you can store at non workplace premises. Carriage of petrol is covered by the Carriage of Dangerous Goods (CDG)[2] and the European agreement (ADR).

Edited by Alan de Enfield
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If the prop fouls on an inboard engine you may have to get into the water to free it although the blade of a serrated kitchen knife fixed into a pole or even a hook in a pole often does the job from the bank. I know because of time on a Thames hire fleet. Although really bad prop jambing at high seed can damage an inboard shaft/drive line in practice it is rare.

 

If an modern outboard prop jambs//fouls it will probably slip on the rubber drive bush and the bush will wear and eventually fail to transmit drive. With a bit of luck it will just about drive the boat at very low speed but then it slips as you increase the speed. I would always carry a spare outboard prop for serious cruising a long way from home.

 

Note the bit about poor or non-existent battery charging from outboards above.

 

Outboard are stolen on a fairly regular basis unless very strongly bolted to the hull with the bolts secured in some way.

 

Trying to fix a broken down outboard in situ is usually more challenging than on an inboard. Dropped tools& parts tend to get lost under the water.

Edited by Tony Brooks
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Thank you for your replies, it seems that I may be overestimating how often you have to clear a blocked prop.

 

It is similar to getting a puncture in your car tyre - statistically, the more miles you do, the more likely you are to get a puncture (fouled prop)

 

Having said that - in 40 years of leisure boating I have had a fouled prop at Sea once, and a fouled prop on the Canals, once.

I have had an engine fire (at sea) once, and once lost a prop off an outboard (coming into a slipway, went into reverse and it 'screwed' itself off)

We very nearly hit a submerged (but floating) container in the Irish Sea.

 

Getting a fouled prop on the canal is absolutely nothing to worry about - 'float' into the side, if it cannot be cleared via the Weed-Hatch' then jump overboard (its only a couple of feet deep) and cut off the 'rubbish'.

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