Wednesday 11 June 2014


The next class of Consolidation engines was the 3600 series.  They were called "N 2a" class: numbers 3600-3690.  Built from 1909-1911, these engines had 63" drivers and cylinders measuring 23" x 32".  Weight on the drivers was 211,000 lbs, some 33,000 lbs. more than the M-4 class.  One locomotive of this class, Number 3651, has been preserved in Lethbridge AB:

Here is another link to a site with many photos of 3600's & 3700's:  Here is one photo from that site of the aforementioned and preserved Lethbridge engine in service, date and place unknown.  Note the foot board pilot and narrow oil bunker to permit a better view for the engineman while doing yard switching.  Gathered cab curtains suggest that winter is coming or going.  Bud Laws Collection.

Here is a CPR Drawing of 3600, class N-2a Consolidations with key dimensions.
These engines were fairly uniform in appearance and were very well modeled by the Japanese firm, United Models many years ago.  I have 3 United Models Consolidations in service, all of which have received some cosmetic and mechanical modifications based on photos of the prototypes.  Here is my version of CP 3629 which has received a larger coal bunker, a smaller water tank hatch, a triangular number board, modern classification lamps, and extra flags.  Mechanical changes include a North West Short Line gearbox and motor.  A Soundtraxx Tsunammi decoder and a micro LED headlamp have been installed as well. 

The prototype locomotives varied slightly in running board configuration and in the arc of the cab skirt.  One more obvious difference was that for some engines, an air-powered reversing gear was installed on the right or engineman's side that necessitated a raised step in the running board.  One of these was the 3628 which received her power reverse sometime before her conversion to oil firing in 1949/50.  Here is our version based on photos of the prototype prior to the oil conversion.  The model tender is mostly stock and close to the 5000 gallon prototype. 
Another model of this N-2a class is 3678, a long time KV engine.  She was converted to oil early in her career, so we have given her an oil bunker from a D-10 tender, a rather simple modeling exercise.  (The tender from our basket case D-10 shown in the last post was used to create a service tender for our steam powered Ditcher.  The D-10 tender requires a lot of work to make it serviceable, chiefly rebuilding the bolsters on the tender floor.  I do not know how or why it was built so poorly because it simply does not stay on the rails, does not carry a coupler at the standard height and often shorts out on all but tangent track.)  But we digress...

Most 3600's were fitted with Open Cabs but a few received Vestibule cabs and 8000 gallon tenders late in life.  Three KV engines in the latter category were 3601, 3609 and 3657. Of course, many were rebuilt into P-1n Mikados in the late forties and served in the final years of the Kettle Valley steam era.

As we mentioned above, to model standard 3600 locomotives, the brass model by United Models is a very good one and can be had through various on-line sites.  We do recommend a new motor and gearbox, the North West Short Line products being a very good choice.  The original gearbox is acceptable but the motor is definitely a candidate for replacement.  Here is the NWSL site: 
Our standard motor is the NWSL 2027 (or the 2032) and their 36:1 idler gearbox number 150-6.  We also install a flywheel.  We use a simple flexible tube for the "universal coupling" between the motor shaft and the gearbox shaft.  This is actually model aircraft fuel line.  Very occasionally this tube wears out or slips or breaks but is easily replaced.

A few detail changes or additions can improve the authenticity of these ladies.  The tender water hatch is oversize and can be replaced with a Precision Scale hatch.  This requires a patch on the lower deck before mounting the new hatch.  The marker lights on the front of the boiler are an old style and could be replaced with Cal Scale modern markers.  Cab curtains will eventually grace our N-2's as will smoke deflectors.  These deflectors were mounted on most if not all KV engines and were used in tunnels and snowsheds to protect the roofs of these structures.  The early version had handles and was manually operated. Later ones had a piston which, I presume, could be operated from the cab.  They are readily visible on many photos of KV/CPR engines.  Many 3600's ran as extras and thus required extra flags.  Our educated guess is that they were about 18" square.  We have fabricated these with crumpled .002" brass shim-stock and .015" phosphor bronze wire.  The number board on CPR locomotives was triangular until 1945 or so.  Because of an accident, flat number boards were designed and installed on engines and few of the older triangular were around after 1950, if any.  Engine 3601 did carry the old style into 1950 as a Gib Kennedy photo attests. 

We have some exposure to the Bachman consolidation and this is a possible candidate for conversion to the N-2.  Its wheelbase, driver size and valve gear are a good match.  One drawback is the size of the boiler which is quite a bit larger than the CPR's.  One can live with it or construct a boiler of your own, but the drawback of creating your own closer to scale boiler is the combination weight and motor mount that would have to be modified.  The running boards need work to approximate the standard CPR style even if you use the Bachman boiler.  The cab is easy enough to modify with styrene.  Sometimes Bachman will sell the chassis and other parts separately:

One weakness of the first run of the Bachman Consolidation locomotive was the brittleness of the wiring harness which often breaks at connections.  It is a good idea to replace the original wire with a more flexible wire (NWSL).  One needs to solder loops on one end or use miniature wire lugs for attaching under the terminal screws to the boiler weight.  This is the a weakness that Athearn's USRA Light Mikado shares.  It is no longer in production but is still available.  This latter is an excellent product and we have used it to produce a CPR P-1n Mikado with another on the way.  The chassis is a possible candidate for conversion to a Consolidation as the wheelbase and running gear is close enough.
The tender of the Bachman Consolidation is huge compared to the CPR 5,000 gallon tender but removing a chunk out of the middle should be straight forward enough to get started

Well, this post is getting long enough and there is still lots to share about the 3700's so until next week when we continue with KETTLE VALLEY CONSOLIDATIONS PART 3.  More drawings and photos.

Coquihalla Man

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