Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Jim

Help with this location please

Featured Posts

On 08/01/2019 at 12:31, Chris Williams said:

A bit like Grandad's hammer that has had two new heads and three new handles, but it's a hundred years old.

I did some work on BWB's 'Water Lupin', which was the front half of 'Gorse', I understand that there are now two boats called 'Gorse', one made from 'Lupin' and the other from the back half.

Water Lupin.jpg

Oft called "Triggers Broom" now but same principle Chris.

 

 

Share this post


Link to post
Share on other sites

One wonders if the Insurers are happy with these 'Cut and Shut' boats.  A friend had a car which said 'Jaguar' on the front, but the rear said 'Daimler'.  He crashed it and it fell apart.

Share this post


Link to post
Share on other sites
On 08/01/2019 at 12:31, Chris Williams said:

A bit like Grandad's hammer that has had two new heads and three new handles, but it's a hundred years old.

I did some work on BWB's 'Water Lupin', which was the front half of 'Gorse', I understand that there are now two boats called 'Gorse', one made from 'Lupin' and the other from the back half.

Water Lupin.jpg

Picture below of the bow section of Gorse whilst being stretched at Stockton. 

FB_IMG_1512310592044.jpg

Share this post


Link to post
Share on other sites

Seem to have gone way off topic!

Ships get lengthened in the same way and because the length/width ratio changes, they often go a bit faster with the same engines.

One assumes the same happens with narrow boats.  Has anyone noticed this effect?  Presumably shortening a boat would make it go slower, or need more power.

 

Share this post


Link to post
Share on other sites

Regarding 'Water Lupin' / 'Gorse', when she was 'Lupin', she had an Enfield horizontal twin diesel, which I was familiar with, since they were also fitted to Lansing Bagnall tractors.  Air cooled and somewhat noisy., The hull had a flat swim end.

Enfield Diesel..png

Share this post


Link to post
Share on other sites
5 hours ago, Chris Williams said:

Seem to have gone way off topic!

Ships get lengthened in the same way and because the length/width ratio changes, they often go a bit faster with the same engines.

One assumes the same happens with narrow boats.  Has anyone noticed this effect?  Presumably shortening a boat would make it go slower, or need more power.

 

Yes, this is correct. There is a mathematic formula for this which defines hull speed based upon length; width, and displacement. The Queen Mary at just over 900ft long at the water line and 118ft beam had a design hull speed of around 34knots. At full speed I recall she would cruise at 32knots. An additional formula shows what the ultimate engine power should be taking in engine rpm; propellor dimensions, and 'slip', which is the difference between the distance forward travelled by one full rotation of the propellor against the slippery wet stuff, along with what is known as a 'fiddle factor', which marine dynamisists argue about dependent on water depth and what they had for breakfast. Complex stuff - especially the last bit.

 

Our boat YARMOUTH was rebuilt from what it was with an 18' swim, and a prop 23" diam x 27" pitch to make the best of the 18hp PD2 with a 3:1 reduction in the available space beneath the counter. On deep water she would fly, not bad on the cut either. A larger diameter with a little less pitch would have been better, but diameter space was the limitation.

Share this post


Link to post
Share on other sites

When I was with Shell tankers we took a 36thousand ton ship to japan where it was cut in half a a ready made section put in and a bulbous bow tacked on the front. Now over 50 thousand tons with same engine using less fuel and little bit faster. 

On the cut the big factor as to revs and speed is water depth my barge at 1200 revs on the smaller French canals does 5 to 7 Klms per hour but on a river 10 at least.

Share this post


Link to post
Share on other sites

Ah, yes - water depth.  Does that include the wet mud at the bottom of our canals?

'Jaguar' had a 3:1 reduction, fine on silted up canals, but I always felt she could have gone faster on the river with 2:1.  Need a gearbox you can change.

She could do a reasonable speed on the Thames, but stopping could be a problem, especially downstream when the red boards were out!  The paddle-wheel effect.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.