The information on the coaling platform in Pembroke is scant. We have a mention that there was one in the 1908 GTR Bridges and Buildings book, with the note “Shovelled into Ten.” There is a turntable-long rectangle on the Grand Trunk Railway’s 1918 Plan of Pembrok (NMC 145203-1) that indicates its location along the engine house lead. After 30 years of looking, that’s all I have found.
Prototype references for coaling platforms in general are thin on the ground. A web search yielded only the one at Alpine, Colorado on the Denver, South Park and Pacific. The 1990’s produced a drawing, and at one time Vintage Reproductions made a kit for it.
The Alpine platform was 34’x16’x2′ (1088 cubic feet), and the platform was raised 4′ above the rail. However, this was the narrow gauge so, perhaps not exactly transferable. Gondolas on that railroad had a capacity of 25 tons, about 712 cubic feet. So, the capacity of the bunker was about 1 1/2 cars, which makes sense as they wouldn’t want to have less than half a car-load when they ordered the next car.
The Canada Atlantic had two series of coal cars, 20 ton and 40 ton. Sizing for the larger car, we will need space for about 1740 cubic feet of coal. The 40T CA cars were 30′ inside length, so 34′ of platform length is a minimum length. However, the plan shows a box about as long as the turntable, so let’s say it was 50′ long. If the platform were 30″ deep, it would only need to be 14′ wide.
The floor of the narrow gauge gondola was 33″ off the rail, and together with a 3’4″ inside height, that would have put the top rail of the car roughly equal with the six-foot top rail of the platform.
On the Canada Atlantic, the bigger cars probably had an overall height of 8 or 9 feet, which is about the same as the collar on the locomotive tenders. Assuming a 30″ deep platform, this would put the floor 5’6″ above the rail height.
With this information in hand, I slapped together some foam core and card for a 50’x16’x9 foot structure, and posed it along the engine house lead. I’ll leave it in place for a couple of weeks to see how it plays.
Pembroke:87 
Rene, wonderful to see your posts on the coal dock. For what it’s worth, the South Park built several coal docks during 1881-1882 along its Gunnison Division, which ran from Como, CO, through Alpine Tunnel to Gunnison, CO. Docks were at Schwanders, Hancock, Alpine Tunnel , Pitkin and a big one at Gunnison. I got into these when attempting to reverse-engineer the 1882 dock at Alpine Tunnel for which there are no photos. We do have photos of 1881/1882 docks at Mt Princeton, Hancock and Pitkin and photos and data indicate a consistent design for them. From what I can determine, the capacity in the small Alpine Tunnel 14’x40′ dock would be easily 2 and very possibly 3 carloads. They piled it high! Around 1887 Hancock’s was taken down; in 1902 Pitkin’s was replaced with an elevated coaling bin; in 1905 Alpine Tunnel’s was lost in a fire and replaced in 1906 with the dock of a different design, which I think is the Alpine Tunnel dock you reference in your post as no plans of the original have surfaced that I know of. Gunnison’s fell out of use by 1910 and Mt Princeton’s around the same time.
Thanks Dave. Yes, the 1905 Alpine dock is the reference for my dock. I’ve since found another reference for a dock of similar size to mine (12×92’) which held 225 tons of coal, if that helps you. Do you have any idea about the operations? Did the railroad simply schedule occasional loading, or was it related to demand?
By the way, like the South Park, the CAR had a number of small docks along its length; I believe some of them were for emergency use, for example if you had to double the hill, you might want to top up on fuel.
There’s not a lot of info on the operations and coaling, unfortunately, but the coal consumption was heavy and must’ve had regular restocking. The South Park’s Gunnison Division had extreme grades, curvature and horrific weather conditions. The heavy trains were eastbound, primarily made up of 12-14 coal cars + combine with up to 3 helpers to climb from Pitkin to Alpine Tunnel. Each tender held a couple tons of coal. Eastbound trains of 4 engines consumed 1+ cars worth of coal, or 10-14+ tons, getting to Como. That was just the daily carded run, extras would’ve added to the daily consumption. Given that, Pitkin, at the foot of the western slope and sending the most tonnage upgrade, seems the most critical coal dock on the Division and must’ve seen a steady stream of cars on company business from the mine to its coal dock every month. In fact it’s why an elevated coal dock was considered in the 1890s and then built in 1902. Westbound traffic back to Gunnison was less about loads, more about returning a lot of empty coal cars and some local traffic, trains were lighter and needed fewer engines and so consumption theoretically was lower in that direction and I’d guess the dock at Mt Princeton at the foot of the westbound climb wasn’t stocked as frequently but still must’ve seen at least a car or two a week. Helpers moved light to get back to where they were needed and added to the consumption. The removal of the Hancock coal dock in 1887 would indicate that operationally a coal dock near the summit proved less critical than those at the bottoms of the grades. I believe that Alpine Tunnel’s coal dock, 4 miles west of Hancock, was primarily there for emergencies, for MOW trains and for the local inhabitants of the company’s facilities as the traffic levels never warranted staging engines up there as I believe was originally envisioned. I hope this all makes sense, it just skims the surface of a very fuzzy and unusual operation. I am guessing if you know tender capacity and numbers of engines running daily you can assess very roughly what your line’s consumption at that dock was and come up with an idea of how often it would need refilling.