Are Bow Thrusters destroying canal banks?

[Jo Gilbertson]

Interesting article in this month's Canal Boat by Steve Haywood on his observations on boats with bow thrusters and the damage he observed to occur to unprotected banksides whilst moving away from moorings.

 

Anyone agree with his observations?

 

Ought bowthrusters be considered as a maintenance liability and charged as an addition on the exisitng licence if there is a case to be made for additional damage?

[Naughty Cal]

Why would a bow thruster cause any more damage to the bankside than an engine driving a prop thus moving water to move the boat?

[Jo Gilbertson]

Why would a bow thruster cause any more damage to the bankside than an engine driving a prop thus moving water to move the boat?

 

I think the 'thrust' of his argument was that the bow thruster forced water directly at 90 degrees into the bank - and was therefore causing more wear than the traditional way of pushing the bow away from the bank by manpower and walking back to take up the helm and pootle away under normal power from the stern - which has a more oblique affect on the bankside.

[Tim]

I would imagine that boats creating breaking wash would cause more damage.

 

Tin hat on and running for cover!

 

Edited to add - The weight of a person standing on a crumbling bank would surely cause damage too!

Oh, and ban bow thrusters too!

Edited September 16, 2010 by Tim

[magpie patrick]

Indeed, but it depends what sort of boat drive is being used. Juno steers with her outboard, and I pull away from the bank by using a quick blip of forward and wheel hard over, which pushed the stern out, then straighten up and back off. This probably does more damage than using the same technique with a narrow boat, where it is the rudder deflecting the water against the bank rather than the propeller thrusting directly.

 

I have used Blackrose's bow thruster to get the bow of his boat out, but most other boats with bow thrusters I've just used my normal technique and reserved the bow thruster for things like winding and mooring in tight spaces

[mrsmelly]

I think the 'thrust' of his argument was that the bow thruster forced water directly at 90 degrees into the bank - and was therefore causing more wear than the traditional way of pushing the bow away from the bank by manpower and walking back to take up the helm and pootle away under normal power from the stern - which has a more oblique affect on the bankside.

 

Bowthrusters are of no use to anyone unless they are not very capable unless they are needed on longer narrowboats than mine, at only seventy feet I find I have never had need for one praps if I buy a 120 footer that will be a different story

As for moving away from banks on setting off I rarely push the nose off first as this leaves the important bit ( The prop ) still alongside and in shallow water. The best way is to leave the front alone push the back end off as you step on then reverse which pulls nose away from bank and then given correct use of engine and tiller move foreward, you will be well clear of bank and go on your merry way. This is only sometimes hindered by very strong winds but I dont boat in heavy winds.

[Naughty Cal]

Indeed, but it depends what sort of boat drive is being used. Juno steers with her outboard, and I pull away from the bank by using a quick blip of forward and wheel hard over, which pushed the stern out, then straighten up and back off. This probably does more damage than using the same technique with a narrow boat, where it is the rudder deflecting the water against the bank rather than the propeller thrusting directly.

 

I have used Blackrose's bow thruster to get the bow of his boat out, but most other boats with bow thrusters I've just used my normal technique and reserved the bow thruster for things like winding and mooring in tight spaces

 

We use a similar technique. Our sterndrive moves to steer the boat, hence when we manouvre to the bank with reverse or away from the bank in forwards the sterndrive and thus the props are pointing at the bank directing the water towards it. I dont see how a bowthruster would cause more damage to the bankside than any out drive or outboard driven boat.

[Neil TNC]

Interesting article in this month's Canal Boat by Steve Haywood on his observations on boats with bow thrusters and the damage he observed to occur to unprotected banksides whilst moving away from moorings.

 

Anyone agree with his observations?

 

Ought bowthrusters be considered as a maintenance liability and charged as an addition on the exisitng licence if there is a case to be made for additional damage?

 

I think poor old Steve must be getting hard up for things to write!...or has April come early?

[RLWP]

We use a similar technique. Our sterndrive moves to steer the boat, hence when we manouvre to the bank with reverse or away from the bank in forwards the sterndrive and thus the props are pointing at the bank directing the water towards it. I dont see how a bowthruster would cause more damage to the bankside than any out drive or outboard driven boat.

 

It may not make a lot of difference, but a prop is pushing water into a free space from the centre of the boat. A bowthuster discharges from a tube very near to the bank itself.

 

I thought Steve Haywood was just off on a rant really.

 

And <gulp> I agree with Mrsmelly. Push the back out, then reverse. Must be a 70' boat owner thing

 

Richard

[Proper Job]

I have been banned from replying to mrsmelly's post

[billS]

No he's wrong - Bow thrusters are beneficial for the general health of the canal in 2 ways. They dredge the canal bottom by picking up silt, and by forcing it against the banks, they reinforce and strengthen them.

Edited September 16, 2010 by billS

[Nine of Hearts]

It may not make a lot of difference, but a prop is pushing water into a free space from the centre of the boat. A bowthuster discharges from a tube very near to the bank itself.

 

I thought Steve Haywood was just off on a rant really.

 

And <gulp> I agree with Mrsmelly. Push the back out, then reverse. Must be a 70' boat owner thing

 

Richard

 

If you be reversing then the effective forward part of your boat, ie: the bit in the foremost direction of which it is moving, is adorned with an propellor. A bow-thruster, in fact.

[RLWP]

If you be reversing then the effective forward part of your boat, ie: the bit in the foremost direction of which it is moving, is adorned with an propellor. A bow-thruster, in fact.

 

Say that again and I'll knock you down!

[Nine of Hearts]

If you be reversing then the effective forward part of your boat, ie: the bit in the foremost direction of which it is moving, is adorned with an propellor. A bow-thruster, in fact.

[RLWP]

Right - outside!!!

[Proper Job]

Calm down Richard........

 

You have a stern thruster

[Guest]

I rarely push the nose off first as this leaves the important bit ( The prop ) still alongside and in shallow water. The best way is to leave the front alone push the back end off as you step on then reverse which pulls nose away from bank and then given correct use of engine and tiller move foreward, you will be well clear of bank and go on your merry way. This is only sometimes hindered by very strong winds but I dont boat in heavy winds.

 

'tis the technique I use too... no doubt someone will be along shortly to say it's not correct....

Edited September 16, 2010 by MJG

[RLWP]

Calm down Richard........

 

You have a stern thruster

 

I have a proper propeller, and that's all. You should know, you've spent an intimate half an hour with it!

 

Richard

[NB Alnwick]

Bowthrusters are of no use to anyone unless they are not very capable unless they are needed on longer narrowboats than mine, at only seventy feet I find I have never had need for one praps if I buy a 120 footer that will be a different story

As for moving away from banks on setting off I rarely push the nose off first as this leaves the important bit ( The prop ) still alongside and in shallow water. The best way is to leave the front alone push the back end off as you step on then reverse which pulls nose away from bank and then given correct use of engine and tiller move foreward, you will be well clear of bank and go on your merry way. This is only sometimes hindered by very strong winds but I dont boat in heavy winds.

 

Don't bowthrusters run on electricity directly from the battery?

Could be useful if the main propulsion engine has run out of err . . .

 

I have been banned from replying to mrsmelly's post

 

No you haven't . . .

[Proper Job]

I have a proper propeller, and that's all. You should know, you've spent an intimate half an hour with it!

 

Richard

I actually cleared it in 5 minutes........

 

I just loved watching everyone else pulling while I cuddled your loverly BMC

 

Don't bowthrusters run on electricity directly from the battery?

Could be useful if the main propulsion engine has run out of err . . .

Obviously, if such a device was to be fitted to mrsmelly's boat it would be hydraulic drive direct from the mighty Beta 43, which needs diese.......

 

Ooopppsss

[GSer]

I dont see how a bowthruster would cause more damage to the bankside than any out drive or outboard driven boat.

 

 

Fair enough, ban them as well

[Keeping Up]

What about thrusting the bow out with a pole against the bank? Surely that would cause even more damage? Maybe we should ban poles as well.

[Nine of Hearts]

What about thrusting the bow out with a pole against the bank? Surely that would cause even more damage? Maybe we should ban poles as well.

 

Normally that's my job while the First mate operates the engine, but use cheap foreign labour if you like. I think you'll find they can't be banned without contravening EU legislation. Much to the chagrin of UKIP.

[RLWP]

What about thrusting the bow out with a pole against the bank? Surely that would cause even more damage? Maybe we should ban poles as well.

 

I can now see that the only way to move boats without causing damage is by horse and rope. I knew there was a reason why they used to do that

 

Richard

[magpie patrick]

I can now see that the only way to move boats without causing damage is by horse and rope. I knew there was a reason why they used to do that

 

Richard

 

errr Richard, have you seen the rope marks around the system...