An Oasis of steam

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Posted by NorthWest on Monday, April 16, 2018 8:59 PM

I'm not sure if they had it in the 1920s or not, but ads that I have found from the 1930s indicate that Alco was the sole Canadian licensee:

http://www.beyergarrattlocos.co.uk/bgpix/alco.jpg

http://www.beyergarrattlocos.co.uk/bgpix/alco2.jpg

I can't see them being considered in the TE-above-all era of the early 1920s with the tank engine variable TE issue, but I suppose it wouldn't be a big deal for pusher service in the Rockies. I guess you could simply put giant weights over driver sets and attach tenders to them at the expense of added length and difficulty in the terminals. 

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Posted by M636C on Tuesday, April 17, 2018 6:11 AM

Overmod

 

 
M636C
The duplex did look a bit like two 2900s...

 

How much information about the duplex has survived?  Are there any drawings, or a description of expected dimensions similar to what NYC produced for the C1a?

 

The duplex diagram appears on page 206 of Lavallee's CPR Steam Locomotives along with a conventional 4-8-4 said to be based on the D&H locomotives.

The drawings are copies of the original proposal drawings and are to scale with a scale included. But no dimensions are given.

Peter

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Posted by DSchmitt on Tuesday, April 17, 2018 6:23 AM

Overmod

 

 
NorthWest
Would MLW or B-P have built CP Garratts? ALCO had the license for any US production (and maybe for the rest of North America?).

 

Did Alco have the license in the 1920s?  I can't see Beyer-Peacock giving them an exclusive license for Canada under any practical circumstances, as the duty on top of the license fees would make a sale even more unlikely.

The question of MLW (or CLC) building actual Garratt locomotives, as opposed to B-P building them in Blighty and exporting them, is a far more interesting one.  ISTR that there were problems with the detail design of some of the larger Garratts, particularly with pivots fracturing cast steel engine beds, that indicated the British firm didn't really have as good a grasp of big-locomotive construction as they thought.  I'd also think native Canadian pride would make a license-built local design and construction highly more likely.  (And likely successful in operation...)

 

I have several books on Garratts which unfortunately are in storage 3000 miles from where I currently live.  

From information in one of them I posted this in another Thread on this Foum

http://cs.trains.com/trn/f/741/t/160916.aspx

"Cast steel beds for some Garratts were manufactured in the USA and shipped to Britian and Europe where the Garretts were assembled.. 

At one time ALCO considered building Garretts for the US market."

 

I tried to sell my two cents worth, but no one would give me a plug nickel for it.

I don't have a leg to stand on.

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Posted by Overmod on Tuesday, April 17, 2018 1:35 PM

Note that the critical issue is fracturing the cast steel beds, not that the beds were present.  Admittedly the loading imposed by a Garratt pivot was not something familiar to the foundrymen at GSC, and there is no particular 'magic' in the metallurgy of a cast steel bed to make breaking impossible.  But it is my opinion that the detail design of the pivot and bearers is one of the most important jobs for a Garratt designer, and the issue becomes particularly important when the locomotive is scaled up to North American proportions.

Note that CPR would not find much advantage in using any Garratt as a pusher; the same geometry that makes them self-correcting in draft creates excessive lateral thrust in buff.  So their advantage would have been precisely where indicated: on the lines in the far Atlantic East, where light bridges and curving, hilly profile greatly restricted use of conventional locomotives (including simple articulated 'Mallets').  Even standard-gauging the EAR class 61 design would give you a locomotive that could essentially run anywhere and do more than the work of a couple of conventional eight-coupled locomotives of equivalent Cooper rating.

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Posted by M636C on Tuesday, April 17, 2018 11:56 PM

Note that the critical issue is fracturing the cast steel beds, not that the beds were present.  Admittedly the loading imposed by a Garratt pivot was not something familiar to the foundrymen at GSC, and there is no particular 'magic' in the metallurgy of a cast steel bed to make breaking impossible. 

I was out photographing a Garratt with cast steel beds last weekend.

It seemed to be running quite well...

It was a former NSW Railways AD60 no 6029, a type illustrated in two advertisements on the cover of "Locomotive" linked above.

I think it would date to about 1954, being from the second order of 25, so 64 years old. As far as I know no pivot on an AD60 has ever failed. I think the South African GMA and GO had cast steel beds also.

At least two AD60 were written off after head on collisions but the damage to the outer ends was extensive. In fact there were five spare sets of cast steel frames since the order was cut back from 50 but after GSI had cast the frames.

The AD60 was intended to run on track suitable for 15 long tons per axle, but this axle load could be increased to 16.25 tons by removing "liners" in the truck pivots. The trucks were not equalised with the drivers but at least were symmetrical.

Peter

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