daffydd2000
New member
Please can anyone tell me where to find out more about jet-drives. I am hopeing to buy an ex-airsea rescue boat and fit a jet-drive.
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JET-DRIVES
- Thread starter daffydd2000
- Start date
Chris771
New member
Try Hamilton Jet Drives. The first jet drive was developed by Sir William Hamilton in the 1950s in New Zealand. Still amongst the premier Jet manufacturers, a lot of them are used in the offshore oil industry and are very reliable. Used a lot in FRCs (fast rescue craft) where it is desirable not to have propellors to mince rescuees.
On my laptop and cannot remember how to do live hyperlink, so you'll need to type it in :
www.hamjet.co.nz
Very good site with lots of information, the jets are sold all over the world.
IF you can stand things made in Italy, then there is Castoldi Jet
www.castoldijet.it
Chris
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On my laptop and cannot remember how to do live hyperlink, so you'll need to type it in :
www.hamjet.co.nz
Very good site with lots of information, the jets are sold all over the world.
IF you can stand things made in Italy, then there is Castoldi Jet
www.castoldijet.it
Chris
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byron
RIP
Aiming to use shallow waters?
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tripleace
New member
Here we go, come on gludy you were the expert on these things.
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hlb
RIP
Oh no!! not again.
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Haydn
<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>
Haydn
daffydd2000
New member
Being as there are no engines in the craft at the present time it will be a good opertunaty to fit the most economical, and yes I do intend to use shallow water. The rivers Severn and Bristol avon, as you should know has the 2nd highest rise and fall in the world, recorded as 40 feet under Bath Bridge. They also have very fast tidal rips around 9-15 knots in places, therefore to operate safly in these conditions I need a craft that can cope with 10-20 knots. I will also be liveing aboard her, so don't want to lose my home because of a fast tidal rip.
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daffydd2000
New member
Thanks for the info. I have just looked them up and filled out their questioner. I hope to get some good info from them. The craft that I am looking at is a 60foot x 14.5 foot double diaganal ex air-sea rescue boat built in 1943. I will be operating in the rivers Severn, Bristol Chanel and Bristol Avon, so need something that is economical but powerfull.
Thanks again
David
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Thanks again
David
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jfm
Well-known member
massive engineering project
Whooaaa! This thread has has taken on a new scale. 20 knots and 60 feet! You need 2x 700hp diesels or thereabouts, and massive jets either the largest Hamiltons or smallest KaMeWas. You wont find these lying around secondhand. Big ££££. And they wont be "economical" in the nissan micra sense. Say 0.5mpg at 20kts.
Will the hull be happy with all that weight in the stern? It probably was designed for much less engine weight, located amidships.
You say 20 knots, but that's planing speed. Is it a planing hull (if designed 1943, when planing boats were rare)?
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Whooaaa! This thread has has taken on a new scale. 20 knots and 60 feet! You need 2x 700hp diesels or thereabouts, and massive jets either the largest Hamiltons or smallest KaMeWas. You wont find these lying around secondhand. Big ££££. And they wont be "economical" in the nissan micra sense. Say 0.5mpg at 20kts.
Will the hull be happy with all that weight in the stern? It probably was designed for much less engine weight, located amidships.
You say 20 knots, but that's planing speed. Is it a planing hull (if designed 1943, when planing boats were rare)?
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daffydd2000
New member
Re: massive engineering project
She was origanly fitted with 3x Vosper-Thornycroft 1200 hp diesels. Yes she is a planing boat with a hull designe of 30 knots. She saw service in the English Chanel. Origanly built as a torpedo boat, but transfered to air-sea recue duties. The inner engine was the only one with a gear box. the port and starboard engines were direct drive. All manovering in port done useing the inner engine only, then when faceing the right way the other two engines were started. She was built when they knew how to build proper boats, LOL . double diagonel 1" thick mahogany boards on oak frames, commonaly known as "naval diagonal".
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She was origanly fitted with 3x Vosper-Thornycroft 1200 hp diesels. Yes she is a planing boat with a hull designe of 30 knots. She saw service in the English Chanel. Origanly built as a torpedo boat, but transfered to air-sea recue duties. The inner engine was the only one with a gear box. the port and starboard engines were direct drive. All manovering in port done useing the inner engine only, then when faceing the right way the other two engines were started. She was built when they knew how to build proper boats, LOL . double diagonel 1" thick mahogany boards on oak frames, commonaly known as "naval diagonal".
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jfm
Well-known member
Re: massive engineering project
ah ok, serious job then!
Why do you want jetdrives? Do you want to go in shallow water? Whatever you do it will be a massive job but would it be easier to fit twin shaftdrive diesels (or triple) so at least you can to use some of the existing engine mounting beams etc etc
Re suggestions from this forum, are you trying to do this on tight budget (ie 2nd hand engines etc) or are you just going to order brand new whatever is suitable like a pair of MANs/KaMeWas?
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ah ok, serious job then!
Why do you want jetdrives? Do you want to go in shallow water? Whatever you do it will be a massive job but would it be easier to fit twin shaftdrive diesels (or triple) so at least you can to use some of the existing engine mounting beams etc etc
Re suggestions from this forum, are you trying to do this on tight budget (ie 2nd hand engines etc) or are you just going to order brand new whatever is suitable like a pair of MANs/KaMeWas?
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daffydd2000
New member
Re: massive engineering project
I will be useing second hand engines, which is why i want to know the correct size of engines to use. see above post for the area that I will be in. Do the engines have to be mounted in the stern or will it be ok to use prop shafts from the centraly mounted engines to the jet drives. Also how do you go astern with jet drives?
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I will be useing second hand engines, which is why i want to know the correct size of engines to use. see above post for the area that I will be in. Do the engines have to be mounted in the stern or will it be ok to use prop shafts from the centraly mounted engines to the jet drives. Also how do you go astern with jet drives?
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qsiv
New member
Re: massive engineering project
I didnt realise any were built with diesels (unless perhaps at the end of the war). My old man always grumbled about going to war with huge petrol engines and several tons of petrol onboard. He did have one that was a bit different - the central engine was electric (again used for manouevring), but more specifically for the final few miles before putting spies and resistance workers ashore - quietly.
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I didnt realise any were built with diesels (unless perhaps at the end of the war). My old man always grumbled about going to war with huge petrol engines and several tons of petrol onboard. He did have one that was a bit different - the central engine was electric (again used for manouevring), but more specifically for the final few miles before putting spies and resistance workers ashore - quietly.
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jfm
Well-known member
Re: massive engineering project
I read your first post but I see nothing in there that means you need jets.
Invariably the engines are mounted at the stern with jets. I suppose you could mount them amidships with long shafts, but I suspect there could be noise/vibration with such long shafts doing say 2000rpm. Never seen this done. In a production boat they wouldn't do it becos the shafts would eat up accommodation space. You will be looking at 2x700-1000hp engines I guess
Jets dont have gearboxes. Usually the impeller is spinning when the engine is running. You go astern by lowering a bucket over the jet outlet, and this deflects the jetstream 180deg so you get reverse thrust. The bucket is a cast metal scoop-shaped thing, operated up/down by teleflex cable etc. Neutral is often a half lowering of the bucket, so there is equal forward and reverse thrust, though some of the bigger installations have a real neutral where the drive is disconnected and the impeller stops.
Suitable 2nd hand engines will be rare, unless you get industrial engines and marinise them. Marinising a non marine diesel of this size is a big job. (When I say "marinise", I mean you need marine cooling and exhaust)
There are some pics I took at Arno in viarregio of 1200hp kamewa jets in Leopards, on B1's site. I'll see if I can find and post a link
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I read your first post but I see nothing in there that means you need jets.
Invariably the engines are mounted at the stern with jets. I suppose you could mount them amidships with long shafts, but I suspect there could be noise/vibration with such long shafts doing say 2000rpm. Never seen this done. In a production boat they wouldn't do it becos the shafts would eat up accommodation space. You will be looking at 2x700-1000hp engines I guess
Jets dont have gearboxes. Usually the impeller is spinning when the engine is running. You go astern by lowering a bucket over the jet outlet, and this deflects the jetstream 180deg so you get reverse thrust. The bucket is a cast metal scoop-shaped thing, operated up/down by teleflex cable etc. Neutral is often a half lowering of the bucket, so there is equal forward and reverse thrust, though some of the bigger installations have a real neutral where the drive is disconnected and the impeller stops.
Suitable 2nd hand engines will be rare, unless you get industrial engines and marinise them. Marinising a non marine diesel of this size is a big job. (When I say "marinise", I mean you need marine cooling and exhaust)
There are some pics I took at Arno in viarregio of 1200hp kamewa jets in Leopards, on B1's site. I'll see if I can find and post a link
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Gludy
Active member
There is no doubt that good jet drives are far better in almost every respect than shafts and props.
The Cara Marine boat, also 60 foot uses two Hamilton jets driven by two 700 hp Cats.
Jets are best used on hulls designed for them - my guess is that to try and put them on an old boat may not only be expensive but probably not viable either.
You go backwards or sideways at any angle you wish by a bucket defelction system - you can have 60% off the forward thrust backwards if youw wish
The Hamilton chap in this country is very helpful and would I am sure be more than happy to answer any questions.
There is a certain amount of old stick in the muds on this forum who cannot imagine life without being 'shafted' if you can manage it, jets are the way to go - they even allow you to dry out but in your case I have my doubts.
<hr width=100% size=1>Paul
The Cara Marine boat, also 60 foot uses two Hamilton jets driven by two 700 hp Cats.
Jets are best used on hulls designed for them - my guess is that to try and put them on an old boat may not only be expensive but probably not viable either.
You go backwards or sideways at any angle you wish by a bucket defelction system - you can have 60% off the forward thrust backwards if youw wish
The Hamilton chap in this country is very helpful and would I am sure be more than happy to answer any questions.
There is a certain amount of old stick in the muds on this forum who cannot imagine life without being 'shafted'
if you can manage it, jets are the way to go - they even allow you to dry out but in your case I have my doubts.<hr width=100% size=1>Paul
jfm
Well-known member
Re: for the record.....
Those who question jets on this forum are not old sticks in the mud. They hold the highest engineering qualifications in the land from the most prestigious engineering institutions in the world, and question some claims about jets on sound engineering principles.
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Those who question jets on this forum are not old sticks in the mud. They hold the highest engineering qualifications in the land from the most prestigious engineering institutions in the world, and question some claims about jets on sound engineering principles.
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burgundyben
Well-known member
You're barking mad.
You dont seem to know much about it either, else you'd already kow what makes water jets go backwards.
it would have to be a big installation, gonna cost an awful lot of dosh (which you may have, I dunno, but does not sound like it as you wanna use 2nd hand engines)
the air sea rescue boats were built in the main by the british powerboat company, they used resorcinal wood glues which are tending to suffer quite a bit now, I know, my boat is a mere 35 years old and I've bort shares in an epoxy resin company to keep her together...
best talk to the british military powerboat trust at Hythe Southampton, they will know alot about the boat and its previous life and engines.
Reckon you might have a chance of getting it running with shafts, but converting to water jets sounds like a project that will never get finished and consume vast mountains of cash.
But please do go ahead cosI 'd love to see it finished.
<hr width=100% size=1>Sod the Healey - I think I'll buy an E-Type.
You dont seem to know much about it either, else you'd already kow what makes water jets go backwards.
it would have to be a big installation, gonna cost an awful lot of dosh (which you may have, I dunno, but does not sound like it as you wanna use 2nd hand engines)
the air sea rescue boats were built in the main by the british powerboat company, they used resorcinal wood glues which are tending to suffer quite a bit now, I know, my boat is a mere 35 years old and I've bort shares in an epoxy resin company to keep her together...
best talk to the british military powerboat trust at Hythe Southampton, they will know alot about the boat and its previous life and engines.
Reckon you might have a chance of getting it running with shafts, but converting to water jets sounds like a project that will never get finished and consume vast mountains of cash.
But please do go ahead cosI 'd love to see it finished.
<hr width=100% size=1>Sod the Healey - I think I'll buy an E-Type.
daffydd2000
New member
Thanks for the info!!. Do you have a contact for the hamilton chap in this country please. I think it would be a good idea to chat with him direct.
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Gludy
Active member
Re: for the record.....
Wow jfm ..... I did not expect a bite so quickly and totally self hooked!
<hr width=100% size=1>Paul
Wow jfm ..... I did not expect a bite so quickly and totally self hooked!
<hr width=100% size=1>Paul
Gludy
Active member
Am I missing soemthing here?
"You're barking mad."
A chap comes to the forum. claims not to know much about the subject and seeks advice .. that sounds sesnible to me not barking mad
"You dont seem to know much about it either, else you'd already kow what makes water jets go backwards."
Thats why he asked the questions.
"it would have to be a big installation, gonna cost an awful lot of dosh (which you may have, I dunno, but does not sound like it as you wanna use 2nd hand engines)"
I fully agree that the chance of it being viable to fit jets on such a boat is remote and costly.
<hr width=100% size=1>Paul
"You're barking mad."
A chap comes to the forum. claims not to know much about the subject and seeks advice .. that sounds sesnible to me not barking mad
"You dont seem to know much about it either, else you'd already kow what makes water jets go backwards."
Thats why he asked the questions.
"it would have to be a big installation, gonna cost an awful lot of dosh (which you may have, I dunno, but does not sound like it as you wanna use 2nd hand engines)"
I fully agree that the chance of it being viable to fit jets on such a boat is remote and costly.
<hr width=100% size=1>Paul
Gludy
Active member
Hamilton Jets - UK
Phone: 01 1342 313 437
<hr width=100% size=1>Paul
Phone: 01 1342 313 437
<hr width=100% size=1>Paul