Paddle wheel question

[PeteThePen1]

Dear Steamboating Friends

We have received the following query and would welcome your help:

"I wonder if anyone can help with an enquiry we had from Lord John Beauclerk who has recently visited our Centre. His great great grandfather invented a new paddle wheel and placed a provisional patent in 1861. As far as he knows the invention was never used and he only has a description of it. He would be delighted if anyone could come up with a sketch of what it may have looked like. I am sure you will see from the description below it is not exactly clear. If anyone knows an engineer out there that could help we would be most grateful?

Many thanks and happy Christmas

Regards

Mark Vesey
Chairman - SMHC


Provisional Patent No 1368 by Lord Charles Beauclerk – May 1861.

Invention to improve the apparatus for propelling vessels at greater speed and using less fuel than any paddle wheel or screw or propeller.

It consists of 8 cranks about 6 feet long (or any given number of cranks) set at an equilateral triangle to each other and fixed to 2 axles resting on bearings which pass through or into the vessel and are placed parallel to each other.

These cranks are coupled together by double coupling rods about 18 feet long and 3 feet apart. On these rods are placed 4 floats, 3 feet by 4 feet in size.

The axles are worked by steam power and give rotary motion to the 3 sets of coupled cranks without. When in motion it is obvious that each pair of cranks will carry the floats fixed to the rods into through and out of the water at right angles to the vessel and will always remain parallel.

It is obvious also that each set of floats is lifted out of the water and replaced in quick succession by the other two. It follows then that 8 floats are always out of the water and 4 in. Thus at each complete rotation of the axle each float has performed a revolution of 12 feet in diameter.

This gives a surface resistance of 48 square feet thereby doing the work of 4 ordinary paddle wheels independent of the advantage derived from direct action, large size and great depth of floats to which may be added slow speed of engine and low paddle box.


Sent on behalf of the Scarborough Maritime Heritage Centre
A registered charity No 1144532.

A company limited by guarantee registered in England & Wales No 06755717
www.scarboroughsmaritimeheritage.org.uk"

Regards

Pete

[fredrosse]

Please pardon my crude sketches, made with Google Freeware SKETCHUP. But I think these show the basic concept of the subject mechanism. Quotes are from the original description:

“It consists of 8 cranks about 6 feet long (or any given number of cranks) set at an equilateral triangle to each other and fixed to 2 axles resting on bearings which pass through or into the vessel and are placed parallel to each other. “

In the attached sketches, there are only two cranks drawn, in GREEN, the long shafts pass thru the ship’s hull, and the short crankpins are rotating together in unison.

”These cranks are coupled together by double coupling rods about 18 feet long and 3 feet apart. On these rods are placed 4 floats, 3 feet by 4 feet in size.”

In the attached sketches, there are two coupling rods drawn, in BLUE, and the four floats are drawn in RED.

”The axles are worked by steam power and give rotary motion to the 3 sets of coupled cranks without.”

In the attached sketches, there is only one set of cranks, but another and another could be added (imagine a single cylinder engine crankshaft, then imagine a three cylinder engine crankshaft, with crank throws set at 120 degree intervals).

The last sketch shows the paddle mechanism fitted to the side of a wood ship hull. With water shown. One must imagine the motion as both shafts turn in unison, dipping the four floats into the water and producing propulsion.

As far as paddle motion goes, this arrangement is very good, indeed better than conventional paddlewheels. However the structural demands on the mechanism, especially when considering the additional cranks which have been omitted from the sketches, would have been prohibitive.

[PeteThePen1]

Dear Fred

Many thanks for your input. The text all really makes sense now that you have drawn it. By the way, if I could use Google Sketchup as well as that I would be right pleased!

Regards

Pete

[fredrosse]

I just ran across an old (1877) publication that also defines this mechanism. Evidently some of these were actually built.