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New Zealand's Answer to the Shay - The Johnston

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New Zealand's Answer to the Shay - The Johnston
Posted by BEAUSABRE on Sunday, August 7, 2022 10:15 AM
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Posted by pennytrains on Sunday, August 7, 2022 6:20 PM

Wowzers!  Never saw an old giirly like that before!

Big Smile  Same me, different spelling!  Big Smile

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Posted by BEAUSABRE on Sunday, August 7, 2022 9:06 PM

Done a bit more research and found this

1896 0-4-0 T Type A
J. Johnston & Sons Ltd. built eight of these lokeys starting in 1896 with the last built in 1927. They were 4-wheelers of about 7 tonnes weight. cylinder horizontal engine was mounted between the frames under the smoke box from where it drove a crankshaft near the middle of the loco, thence through herringbone gears onto a central jackshaft below. This gear ratio was 13:30. The jackshaft, located midway between the two sets of driving wheels, then drove through side rods to the wheels. The loco usually towed a 4-wheel tender holding water and fuel but at least four engines operated as tank locos. More & Sons converted their Johnston A's to 0-6-0 arrangement fitting a pair of flangeless wheels to the jackshaft thereby increasing adhesion. The average service life of these types was about 37 years. One is now on static display at Riverton, near Invercargill and another resides at McLeans Island.


1911 Type B 8-Wheeler Only two Type B locos were built (and at least one model) giving a similar lokey to the Type D but for use on heavier steel rail. The boiler was offset on the frame, in a similar fashion to the Shay, to allow the two-cylinder engine to be mounted on one side. The transmission was the same as used on the 16-wheeler.

The second lokey, built in 1911, lasted in service at Cape Foulwind until 1927.                                                                                                                                                                                                                                                   1910 Type D 16-Wheeler

Designed as a replacement for horse teams, the axle loading of 1 tonne per axle was arrived at as being similar to that achieved on log buggies. The loco weighed in at 16.25 tons. A twin-cylinder vertical marine type engine was cab mounted and drove a longitudinal crankshaft that in turn drove an intermediate shaft via spur gears giving two speeds of ratios 1:1 and 1:2. The intermediate shaft then drove another set of spur gears down to the level of the line shaft. The lower, larger gear was 3�6� (1067 mm) in diameter. The line shaft was set just above the truck axles and a bevel gear pair drove from the line shaft to a stub shaft aligned across the truck. A pair of spur gears then transmitted power down to the axle. In all a total of 38 gears were in the transmission. The use of bevels on the stub shaft gave rise to high tooth stress and rapid wear. The wheels were carried on four trucks, the front two trucks being joined by a beam pivoted on the trucks and again at its mid-point where it was attached to the loco frame. The rear trucks were arranged the same. Top speed was about 5 mph (8km/h) and the average service life about 23 years. None exist today.                                                                                                                                                  Those wheels look like they came off a hand car! It would be quite a challenge for any model railroader (I don't think any manufacturers offer a model)



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Posted by samfp1943 on Friday, September 9, 2022 9:24 PM

BEAUSABRE

"At least 16 were built between 1910 and 1937."

It would seem that the Question, Unasked Whistling 

While the response to that Question seems unanswered??? Sigh

Do any of the Johnston-built 'Lokeys'  exist Today?  

Inquiring Minds would be curious ...Whistling

 

 

 

 


 

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Posted by BEAUSABRE on Saturday, September 10, 2022 9:37 AM

 

samfp1943
Do any of the Johnston-built 'Lokeys'  exist Today?

                                                                                                                                                                                                                                                                   Your wish is our command, my little swamp turnip 

 

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Posted by pennytrains on Sunday, September 11, 2022 7:16 PM

Swamp turnip?????  Tongue Tied

Big Smile  Same me, different spelling!  Big Smile

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Posted by Overmod on Monday, September 12, 2022 8:36 AM

pennytrains
Swamp turnip?????

Loosely derived from the French 'p'tit chou'

It might make a little more sense if you know the woid of the day is "Valheim".

The sixteen-wheelers are just geared engines with a single longitudinal shaft driven from a modified launch engine.  The most expensive part was the bevel gears, the source of which ought to be determined.

A very similar drive arrangement, without universals in the lineshafts, was used on the original PRR steam turbine-mechanical V1... but that design used two engines, one per cast underframe.  The chassis was very similar to the one provided for the prewar Essl modular locomotive (which deserved better than it got, just like the 412 engines that went before the 408s) -- that chassis wound up under the original Centipede with far less horsepower than practical.

New Zealand had a very successful railway that was run on American principles with American equipment.  They also had a government railway run on British principles.  Unfortulately the latter acquired the former; I think it is illustrative that they took the electric lighting out of the passenger equipment and didn't provide a practical substitute for nigh on 20 years.  (See "When Steam was King" for the gory details.

Mind you, I love New Zealand, and its engines included the first true Atlantic, the justly redoubtable A class, the K 4-8-4s, and the Ja 4-8-2s, any of which are at the top of the pantheon of Cape gauge power.  

Aside from the "1066 and all that" dotty Engilish attempt to use Vauclain type 1 cylinders for 'massive power gains, perhaps the most 'more English than the English' exploit was the Garratts.  Much bigger Garratts than any other power.  With three cylinders per engine.  And all sorts of auxiliary bells and whistles... the thermodynamic gains for which were apparently stacked to produce the overall "efficiency" the locomotives were to deliver.  Stewart quoted one person as saying words to the effect of "My God, she'll be puffing pound notes out of her stack."  The reality was not as sanguine... which is a shame because the engines were probably superior to anything the runners-up in the Cape gauge category had, including the famous GMAMs.

While on the subject of advanced geared engines in New Zealand, a German firm apparently quoted a very large geared engine, as I recall for the Rimutaka Spiral Fell system, in 1935.  I have never seen anything but the brief description and side elevation diagram in the book, but it would make a fascinating scratchbuilding project for someone.

 

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