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Author Topic: Bowman model steam boats  (Read 1072 times)

trelawney

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Bowman model steam boats
« on: August 13, 2019, 03:52:20 PM »

Would be interested to know what type of wood may have been used in their constriction and also if the curved sides were likely to have been formed by steaming ?


Thank you


Trelawney
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frazer heslop

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Re: Bowman model steam boats
« Reply #1 on: August 18, 2019, 09:43:00 PM »

The couple I have are Pine
The early boats have bent planks for the sides and often end up pigeon toed as they distort as there is no bulkheads fitted
The later as in Snipe ,Eagle and the one I always forget are cut from the solid like Russian dolls and you can often see the saw marks on the inside of the hull
No idea what the Luton Bowman boats are
For a brief period around 1924/6 from memory the hulls are carved out from a solid board and according to folk lore Mr Jenkins was not amused by the waste but it kept the shop warm. These hulls are fairly rare as they suffered from shaking
Basil Harley did a build in Model Boats that had the sides steam bent to shape
Tony Bird has done a thread on the toy forum and he steamed the boards worth a look at for ideas
Hope that helps
kind regards
frazer
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trelawney

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Re: Bowman model steam boats
« Reply #2 on: August 19, 2019, 08:07:38 AM »

Thank you Frazer - most helpful and appreciated.


Trelawney
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roycv

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Re: Bowman model steam boats
« Reply #3 on: October 16, 2019, 06:22:19 PM »

Hello I see you made reference to the Basil Harley plans (Sea Jay) in Model Boats quite while ago now.  I built one as per the plans and I steamed the hull sides.  I used 9 ply plywood ( about 10 mm) which is not flexible.  I made a steam chest from copper tube more like a cylinder and also a simple jig for the curved bow.
 
After about 10 minutes the ply came out like wet paper but only for about 10 seconds so it was easy to get into the jig, after cooling it was removed.  Then the second side was steamed and fitted upside down into the jig.  They were allowed to dry and then building commenced as per the plan.

I intended to have a steam plant but even with a relatively light steam engine a special bespoke unit was too heavy.  This meant that the 3 piece aluminium (or tinplate) s/s was rather difficult.  I decided to go electric and opted to use a vintage electric motor, a Bassett-lowke Marine motor.  This is a good combination with a 7.2 volt battery pack.
After some thought I decided to have a one-piece wooden deck to make the s/s more stable.

The stern houses a rudder servo with a small extension that activates a chain system contained in tubes connected to a sawn up Meccano 2 inch pulley, which is in effect the rudder stock  There are some small springs at the end of the chain to keep the tension in the system.
The steamed curve of the bow is absolutely stable but as there is so much allowance in the s/s for air to get into a possible steam plant.  I think the model is about 25 years old now but I only sail the boat on a small club lake.

regards Roy


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trelawney

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Re: Bowman model steam boats
« Reply #4 on: October 16, 2019, 06:35:40 PM »

Roy


Many thanks for the post and the food for thought.


Well timed as starting on it very shortly.


Trelawney
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roycv

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Re: Bowman model steam boats
« Reply #5 on: October 16, 2019, 06:54:28 PM »

Hi Tralawny another option to steaming is to use thinner wood grain verticle and enough layers to build up the thickness required, but built on a curved jig surface. 

You could cut the jig from hard foam and face it with thin ply and then cover with clingfilm to stop the glue adhering.  Just make sure you make a right and a left side!
If you are going to have a steam plant then weigh it with water in the boiler and see if it is a feasible weight to carry.
You could adjust the bottom of the boat down by half an inch to give you greater displacement, that would give another 2 pounds of weight for the boat to carry but it might be a bit sluggish in the water.

My boat runs nicely using using maybe 8/9 watts.

Good luck,
Roy

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frazer heslop

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Re: Bowman model steam boats
« Reply #6 on: October 16, 2019, 07:48:31 PM »

I also used Basil Harleys hull just a few inches shorter for a Bowman look alike with a simple steam plant
A brief run through can be seen here  [size=78%]https://www.tapatalk.com/groups/freesteammamod/bowman-sea-hawk-eagle-t4828.html[/size]
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