(https://i.imgur.com/0H14f06.jpg)
I compared the chassis from the Bachmann "N" Percy and the dummy 0-4-0 chassis from the Kato 10-503-1 Pocket Line Steam Passenger Train Pack and thought they were a close enough match to be used together for an articulated locomotive.
(https://i.imgur.com/NlJf0xV.jpg)
I measured the two chassis (the wheels are slightly different in diameter) and compared them with the body of the "Skylark" from Model Engine Works on Shapeways as a Mallet configuration.
(https://i.imgur.com/kFmCjgI.png)
It didn't look quite right – the boiler would require a long extension. Well, I already have two Mallets. how about a Kitson Meyer instead?
(https://i.imgur.com/qQqhnCf.png)
This looked much more interesting. I lined up the two chassis against the body and decided it would be workable with the Percy chassis as the forward unit.
(https://i.imgur.com/YlrCVrk.jpg)
I had to cut up the body; I first sawed off the bunker (and later on I sawed off the rear of the cab).
(https://i.imgur.com/vCfXmQL.png)
(https://i.imgur.com/zmlDnz9.jpg)
A rectangle of 40thou plasticard holds the whole thing together as a footplate; a cut-out fits round the Percy chassis and a large hole prevents the Kato chassis fouling as it pivots– the top of the Kato chassis is taller than the frame. The pivot is a 10BA screw that goes up through the forward hole in the Kato chassis and through a 10BA nut fixed in position as seen in the photos. The two halves of the Kato's chassis are kept from falling apart by the longer of the two original screws passing up the other hole and into a small piece of 40thou plasticard (shaped so as not to foul the rear of the bunker).
I thought the bunker looked over large, so I cut the rear of the cab off the print (as mentioned above) Moving it back about 5 mm makes the bunker look better – and gives the crew more space in the cab!
(https://i.imgur.com/e9NbwPt.jpg)
The boiler and tanks are filled with lead and Liquid Gravity to give much needed weight and some stability. 40thou plasticard forms the sides of the new bunker.
(https://i.imgur.com/ytj65pi.jpg)
I must get round to removing the front coupling and installing a Greenwich one! And I have yet to decide whether or not to install a rear chimney.
A very attractive engine it is, too!
I consulted a technical reference I have on my bookshelf regarding your choice of Kitson-Meyer over Mallet. The author considers all varieties of articulated locomotive including Garratt, Mallet, Triplexii and other exotica. He concludes that the Kitson-Meyer layout is technically superior to all others.
Lt Col Kitson Clark was of course completely unbiased in this matter.
Ian
Thank you.
It's been pointed out that since the front unit is fixed to the body, it's strictly not a Meyer (but then my 0-8-8-0 mallet is strictly not a mallet, either!)
Quote from: hughn on July 24, 2021, 20:19
Thank you.
It's been pointed out that since the front unit is fixed to the body, it's strictly not a Meyer (but then my 0-8-8-0 mallet is strictly not a mallet, either!)
We're not going to let minor things like that bother us are we!
Rule 1 applies. :)
Quote from: hughn on July 24, 2021, 20:19
It's been pointed out that since the front unit is fixed to the body, it's strictly not a Meyer (but then my 0-8-8-0 mallet is strictly not a mallet, either!)
True. Sort of the opposite of a Mallet, which has a fixed rear frame and swinging front one.
I consulted the encyclopaedic authority on this, Lionel Wiener's 1930 book 'Articulated Locomotives'.
At first sight it wasn't encouraging. This is on p307:
SEMI-ARTICULATED LOCOMOTIVES WITH TWO SETS OF DRIVING WHEELS, OF WHICH THE REAR ONLY IS MOBILE
A number of patents have been taken out for locomotives on this principle although, up to the present, none of them has been satisfactory. (He goes on to discuss six example types.)
Then it dawned on me. Wiener only researched the locomotives of Roundworld; he had never studied the successful locomotive fleet operating in Angst-Lesspork! (Sadly, Wiener died in 1940, so we won't get an expanded version of his book that includes them.)
Looking forward to seeing the maybe-a-Kitson-Meyer when it's complete.
Ian
Quote from: hughn on July 24, 2021, 20:19
Thank you.
It's been pointed out that since the front unit is fixed to the body, it's strictly not a Meyer (but then my 0-8-8-0 mallet is strictly not a mallet, either!)
Kitson-Meynot, perhaps?
Alternatively Kitson-Meybe?
Whatever it is it looks good to me!
Just out of interest; what distinguishes a Kitson Meyer from (just) a Meyer?
Quote from: hughn on July 26, 2021, 10:26
Just out of interest; what distinguishes a Kitson Meyer from (just) a Meyer?
I think it is to do primarily with the location of the firebox -
https://en.wikipedia.org/wiki/Meyer_locomotive (https://en.wikipedia.org/wiki/Meyer_locomotive)
(https://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/Meyer_loco.png/450px-Meyer_loco.png)
(https://upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Kitson-Meyer_loco.png/330px-Kitson-Meyer_loco.png)
Just a thought, but being a flatworld and doing things differently, I see the location of the cylinders are reversed. Does it make it a Nostik-Reyem locomotive?
Quote from: hughn on July 23, 2021, 21:24
And I have yet to decide whether or not to install a rear chimney.
Being (moderately) serious about this topic for a change, I would say not.
Quite long Garratts with the cylinders pretty much at the extreme ends still take the live steam all the way there from the regulator and return the exhaust steam all the way back to the blastpipe (even though long jointed steam pipes must be awkward to keep steam tight). Presumably the need to maintain draught through the boiler tubes outweighs any inconvenience.
Your Kitson-Meyer has most of the heavy stuff at the front, with the weight of the boiler and smokebox taken on the front power unit while the rear one only has water and coal to weigh it down. That must make the rear unit slightly at risk of slipping, in which case, you definitely want to have as much draught through the boiler as you can get while the rear cylinders are wasting live steam.
Just my $0.02 worth (in Ankh currency). As Peter points out - Rule 1 applies here!
Ian
Edit to add: Contrary to my arguments above, I've since found a photo of a Kitson-Meyer with a second chimney at the back. It's from Wiener's 1930 book Articulated Locomotives. The author talks a lot about articulation issues but nothing at all about draughting, so I really don't know if my argument above has any merit or is totally bogus!. Photographic counter example below.
Quote from: hughn on July 26, 2021, 10:26
Just out of interest; what distinguishes a Kitson Meyer from (just) a Meyer?
Graeme has pretty much answered the question. I can add a couple of details.
Wiener and Kitson Clark both point to Jean-Jaques Meyer's original 1862 design and to a number of examples built in the latter half of the 19th century. The key feature is that the mass of the boiler and firebox is fairly central over the two powered bogies and the cylinders are on the inboard ends. Wiener offers the example drawing below. Note that the live steam path is nice and short - the cylinders are almost directly below the dome. However note also that the firebox sits on top of the rear driven bogie, which both limits its size and makes the grate fairly awkward to get at.
What makes a Kitson-Meyer is essentially being built by Kitson & Co of Leeds or under licence from them. Again both Wiener and Kitson Clark state that the position of the firebox between the powered bogies is the important point, allowing it to be bigger, deeper and more accessible. The cylinders are placed either to the rear of each bogie or at the outer ends. The photo below (from Kitson Clark's paper) shows the very first Kitson-Meyer, built in 1894. Being 3'0" gauge, space for the firebox was probably quite important. Kitson Clark states the firebox position as being the USP of this design.
Confusingly, Wiener refers to Kitson-Meyers as Meyer-Kitsons! Lt Col Kitson Clark uses the former designation, but he was Lord Kitson's grandson!
Ian
Thanks, chaps!
There's never a dull moment with articulated locos!
There are other books to consult apart from Lionel Weiner's classic work. These are from Trackside Publications, which ceased after Donald Binns' death.
They are -- (1) Meyer Articulated Locomotives - A Definitive history by Donald Binns & Gunther Koch ( published 1997 )
& (2) Kitson Meyer Articulated Locomotives by Donald Binns
1st edition 1985
2nd edition ( revised ) 1993
3rd edition ( revised and enlarged ) 2003.
The best version is the 3rd edition. but all contain photos of the many variants of the design, ie opposed bogies with cylinders inboard, opposed bogies with cylinders outboard , bogies with cylinders on the trailing end, bogies with cylinders on the leading end, some with a 2nd chimney and some without, and of course a multitude of wheel arrangements.
Kitson Meyers were most popular in South America;
Mallets ruled in North America ; Beyer Garratts in Africa
Garry
Could I respectfully ask that if anyone wishes to debate the pros and cons of 3D print quality, they DO NOT clutter up this thread; start a new one!
Thank you.