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Author Topic: Paddle Tug Monarch (1833)  (Read 3681 times)

flashtwo

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Paddle Tug Monarch (1833)
« on: June 17, 2016, 05:26:12 PM »

Hi Mayhemers,

Having completed the Edwardian Steam Launch "Vital Byte 10" (see thread http://www.modelboatmayhem.co.uk/forum/index.php/topic,37563.50.html ), I have been inspired, to build a new steam model, by the design for the new £20 note that features J M W Turner's famous 1838 painting of the Monarch steam tug pulling along an old hulk on the River Thames.

Having done a little bit of research and buying a copy of "The Rise and Fall of the Paddle Steamer" (Nick Robins), I have begun construction of a side lever steam engine based on components of the Stuart Beam engine.

The side lever engine is really a beam engine (think James Watt), but with two beams very low down by the sides of the cylinder in order to lower the centre of gravity. The cylinder is 1 inch diameter with a 2 inch stroke.

It is early days yet, but the broad plan is to get the engine under steam using "Vital Byte's" vertical boiler, then build its own horizontal boiler and then a 6 ft clinker hull as per the original. The actual design will be based on Turner's painting and also early paddle tug pictures. There will be a bit of artistic licence, but I hope to retain the essential essence of the period.

As usual any advice, especially at this stage, will be most welcome.

Ian
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Capt Podge

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Re: Paddle Tug Monarch (1833)
« Reply #1 on: June 17, 2016, 05:35:41 PM »

Hello Ian.

I'm afraid I won't be able to give any advice on this as I have no experience of this type of build - I will however, look in as you progress because it looks to be a fascinating subject.

Good luck with your endeavour.

Regards,

Ray.
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #2 on: June 17, 2016, 11:40:35 PM »

Thanks Ray for your interest.

Here's a dilemma straight away.

Turner's Painting (colour) shows the Monarch with the pole mast astern of the funnel, but the Willmore print (based on some sketches by a "mechanical marine artist" named Duncan), shows a "corrected" view of the mast in front of the  mast. Another painting by Reeve showing the Temeraire being broken up, shows a paddle tug side view, which supports the Willmore layout rather than Turner's.
Turner does seem to apply a lot of artistic licence as with his painting of the GWR locomotive in "Rain, Steam and Speed", which to my mind has always shown the firebox to be at the front of the locomotive.
I'm inclined to go with the Willmore print, but that's the engineer rather than the artist in me.

Ian.
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Colin Bishop

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Re: Paddle Tug Monarch (1833)
« Reply #3 on: June 17, 2016, 11:43:01 PM »

Don't rely on Turner for accuracy. His paintings are wonderful but they are intended to convey an impression at the expense of detail.

Temeraire's masts are much too thin and intended to give an ethereal effect which they do. Still my favourite painting though.

Colin
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #4 on: June 17, 2016, 11:57:13 PM »

Thanks Colin...

You don't know if anyone has a 1:12 scale model of the Temeraire that is in need of towing (not to the breakers though!).

Ian.
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tugmad

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Re: Paddle Tug Monarch (1833)
« Reply #5 on: June 18, 2016, 07:02:01 AM »

Alexandra towing ltd  Gravesend has a model of the Monarch in a glass case,I did some repair work on it a few years ago after it got dropped.
I am sure that they could help with a few details for you.
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tigertiger

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Re: Paddle Tug Monarch (1833)
« Reply #6 on: June 18, 2016, 07:32:21 AM »

This relates to a different Paddle Tug, PT Dromedary. Reply #3 on this page of the Paddleducks website http://www.paddleducks.co.uk/smf/index.php?topic=3980.0
You may get some details off the photo or follow up with the Science Museum



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KNO3

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Re: Paddle Tug Monarch (1833)
« Reply #7 on: August 26, 2016, 09:21:14 PM »

It's very nice to see a less usual steam engine being built. How is this project going along?
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TurboTyne

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Re: Paddle Tug Monarch (1833)
« Reply #8 on: September 05, 2016, 05:47:39 PM »

Hi Ian

Looks like another interesting project. Are you following plans for the engine or making your own design?

I visited the Denny shipyard museum earlier this year and saw this side-lever engine built by Napier in 1821.
http://www.geograph.org.uk/photo/1135887

Do you plan to use another electronically controlled monotube boiler in this boat?
(I've been doing a lot more with PICs since you got me started on them a few years ago).

No doubt you've seen this, but, just in case, this page at the Science Museum seems to refer to a contemporary model of the Monarch.
http://www.scienceandsociety.co.uk/results.asp?image-10266183

Regards     Mike
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #9 on: October 01, 2016, 10:25:24 AM »

Hi Mike,

Thanks for your lead to the Science Museum - no I hadn't spotted it.

I've received three images of the model and the invoice describes the model as scale 1:64, though the description of the 10266183 image says "This is a replica of a contemporary model (scale 1:96) of the 'Monarch', built of wood for service as a tug on the river Thames."

Originally, I had e-mails from Jasmine Rodgers (Image Executive), who said the images were old undigitised black and white slides and it would take a fortnight to have them processed, also, if I wanted new photos it would cost £50+VAT  and that also depended on the conservation department agreeing.

Then she e-mailed to say that we in luck that the model had recently been digitally photographed and three new images were available.

There were very trusting in that they sent me the image files and then the invoice. They are very inquisitive regarding the use of the images. Because of copyright, I'm limited to using them for research - display is limited to the "Model Engineer Exhibition" (i.e. Judges' Notes) and then I must give credit to the Science Museum!

The images are very clear and show a water-line model and in particular the peculiar steering method of a rail-mounted truck filled with old chains, which would be moved across the beam to lift one of the paddles out of the water to give a tighter turn. The truck is adjacent to the ship's wheel so perhaps there was some sort of rope pulley system - this will be an interesting part to radio control!

Mayhemer Boneash has done some research, which has lead me to the Bolton and Watt Collection at Birmingham Library. In the collection there is reference to a "table of timber" for a Monarch (1833). There was a Monarch ship of that period and Bolton and Watt tended to list ships that had their engines installed, so I suspect it is not our tug - I shall enquire though.

Regarding the engine, I'm still trying to determine whether it had cross-head slides or the more common parallel motion linkages of the period. Because of the twin side beams, I can't use the normal Watt's parallel motion, so I'm in the process of producing a spreadsheet to calculate the geometry of one based on a short radius arm.

In the book "The Coming of the Comet" by Nick Robins, the model of the Monarch in the Newcastle Museum is described as having a cover over the crosshead slides - this may be an assumption, since the engine may have not been part of the model.

I will be using the monotube system as on the Edwardian Steam Launch, I will just unplug the electronic controller and transfer it to the tug - perhaps just adjusting the control parameters.

When researching, I'm continually amazed at the engineering competence of the late 18th/19th century pioneers. You start off thinking that they were a bunch of enthusiastic amateurs, few in number, working by themselves in dimly lit workshops and then you discover that behind them were complex organisations with design offices and draughtsmen as well as the filthy foundries.

Anyway back to the spreadsheets!

Ian.




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ballastanksian

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Re: Paddle Tug Monarch (1833)
« Reply #10 on: October 01, 2016, 03:40:20 PM »

Paintings are often like TV programs and films in that they portray an essence and not necessarily an accurate representation of the subject.The Anthony anthony roll depicting Henry the Eighth's fleet in 1545 would have been the ultimate reference for large ships of the period if ony he could draw! There is enough information to differentiate certain types of vessel, but beyond that they are flambouyant 'shippes' all a'flutter with pennons and heraldry.

This is another topic that has popped up from you inrecent days fellow Ian. I look forward to seeing your work.
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #11 on: October 12, 2016, 10:30:51 AM »

 Hi Mayhemers,

Well, I’ve completed the spreadsheet “model” of the parallel motion with the short radius arm that in some Victorian texts is described as the “bridle”.

Initially the trigonometry just wouldn’t work out until Mayhemer Boneash (while in the George and Dragon “design office”) drew my attention to the extra linkage length between the parallel motion and the piston cross-head (from joint D in the diagram below).

Comparing the various side-lever engine pictures with the normal parallel motions, you could see the extra length was deliberate, so I modified the spread sheet to include it. I then adjusted the extra length and found the optimum proportion to give the minimum deviation of the cross-head movement relative to the perfect vertical piston movement.

In the diagram the “half beam” is AC, and the parallelogram is BCDE. The “bridle” is EF with the fulcrum at F.

I’ve modelled the dimensions of the actual castings I will be machining and for a beam radius of 90mm and swing of +/-17 degrees (i.e. 52mm/2 inch stroke), the model shows a deviation of less than +/- 0.01 mm (+/-0.4 thou’).

Obviously, the greatest cause of deviation will be the accuracy of machining the linkages themselves, but with the spreadsheet model, I can do the “what-if” type calculations and fine tune the model.

The first graph shows the optimum horizontal deviation (in thou’) from the perfect motion against the +/- 17 degree beam movement. The second graph shows what happens with a ridiculously small change of 0.05mm in the bridle length.

I’m still researching whether the Monarch had the above parallel motion or a cross head slide – I’ve ordered the book “British Steam Tugs” by P N Thomas to see what was going on the early 19th century.

Ian.
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #12 on: October 12, 2016, 01:04:31 PM »

 
…and another graph showing the effect of directly connecting D to the cross-head resulting in a deviation of nearly 24 thou’.

Ian
 
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #13 on: December 16, 2018, 07:37:53 PM »


 Hi All,
Finally back on this project after my Carpal Tunnel hand operation 18 months ago (and having caught up on other household projects!).

I've carried out more precise measurements of the beam trunnion centre-line and cylinder location (using the milling table x-y movement and laser guide) and fed the data into the spreadsheet that calculates the parallel linkage dimensions and displays the cross head variation.

Having explored various locations of Link "B" on the spread sheet, I settled on the optimum variation of the vertical cross-head movement and then committed myself to modifying both beams to accommodate the “B” location.

Based on the spreadsheet data, I made some jigs to assist in the accurate fabrication of the various links – this required total faith in my mathematical modelling of the parallel motion geometry.

As you can see from the Cross head variation graph, the greatest deviation from the vertical was calculated to be +/-0.17 thou’ (+/- 0.004mm) for a beam movement of +/- 16.9 degrees and piston stoke of 51.69mm.

Having made and assembled the linkages I then assessed the vertical deviation on the milling table by illuminating, with the Laser Guide, a length of 0.4mm dia. wire attached to the crosshead.

The alignment was perfect (within the limits of my eyesight and a magnifying glass) – my faith in the trigonometry calcs paid off!

There was a slight error at the highest position of the cross-head, which was traced to the mechanical deflection of Fulcrum “F” which is located 118.36mm above the base – this will be subject to some diagonal bracing just like on the real ships engines.

I had a couple of serendipity moments when I found that the existing cylinder base mounting bolts were in the exact calculated location (68.301mm v. 68.3mm) for the “F” fulcrum horizontal location, and the other for the exact location for the proposed bracing rods between the “F” fulcrum supporting columns and the main trunnion bearing housing.

The next stages will be threading all the rods and then progressing onto the other end of the beams for the crank mechanism.

The attached photographs show the engine at both beam angles.

Ian.
 
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raflaunches

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Re: Paddle Tug Monarch (1833)
« Reply #14 on: December 16, 2018, 07:50:32 PM »

Great to have you back Ian :-))
Looking forward to your continued build.
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flashtwo

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Re: Paddle Tug Monarch (1833)
« Reply #15 on: December 16, 2018, 10:15:45 PM »


Thanks Nick - I'm might even make it back to Wickstead!


One correction regarding the wire diameter attached to the crosshead to gauge the vertical alignment - it was 0.122mm (4.8thou') and not 0.4mm diameter. If I made the laser beam too narrow I couldn't see it even with the lights turned off!




Ian.
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