I am grateful to RME for his earlier post regarding the Rimutaka incline....
I have visited New Zealand, but I don't think I've seen the H class...
I'm Australian and the relationship with New Zealand is best summed up by the saying "I support two teams, Australia and whoever is playing New Zealand..."
A good friend at school had a Tuatara, a small lizard like reptile that appears on the NZ five cent piece. His father was an NZ born professor of zoology. He was also a railfan and I saw numerous photos of the end of NZ steam, and of H199 on open air display.
Later, maybe fifty years ago, I was loaned a copy of "When Steam was King"...
as RME put it
"Most of what I knew about the Fell system was out of Stewart's When Steam was King (otherwise notable for coverage of the infamous pound-note-puffing Garratts and "E66 and all that")."
Many of the illustrations were Stewart's oil paintings: one that came to mind illustrated a locomotive with an early arc light headlight (maybe an A class) entitled "Light of the World".
The Garratt reference was to a junior draftsman who was tasked with determining the combined economies of the various devices fitted to the NZR Garratts and came to a total greater than 100%, and the response was that of the CME when told the figure.
E66 was an odd Mallet 2-6-6-2 tank locomotive which had Vauclain compound cylinders on each unit and a Vanderbilt corrugated firebox (what could possibly go wrong) which was tried as an adhesion only alternative to the Fell locos on the incline. "E66 and all that" was a reference to a well known comedy book on British history "1066 and all that" which conveyed a lot of dull dates in an amusing manner.
Perhaps I had a vague memory of the hand brake wheels in the brake vans and transposed that to wheels used for braking. But the photo of H199 does confirm my recollection of a horizontal bullhead rail as the Fell adhesion rail.
M636C
RME's link "this contemporary account", shows the ruling grade to be 1 in 12 or 8.3%. This is well within American electric railway (i.e. street and inteurban) experience with operation by adhesion only. One very important caveat is that none of the grades of such magnitude in American electric railway practice involved a change in elevation of anywhere near the 1,800 feet in the Snaefell line.
- Erik
daveklepperJogging my memory a bit more, the Snaefell was originally built as a steam railroad with the full Fell System. Upon electrification, tests determined that normal adhesion operation was feasible, but the Fell Rail was retained for braking purposes only.
Well, originally planned as steam, and built with the aid of a steam engine, but not actually built to use steam. And the Fell rail was used for both emergency braking and emergency guidance (they go into detail about the wheels). See this contemporary account.
A system of 'rheostatic' (dynamic) braking was set up to supplement the friction brakes in 1970.
I notice that neither the emergency brakes nor the emergency guidance appear to be either automatic or foolproof! Ye Gods!
Jogging my memory a bit more, the Snaefell was originally built as a steam railroad with the full Fell System. Upon electrification, tests determined that normal adhesion operation was feasible, but the Fell Rail was retained for braking purposes only.
The Feel rail at Snaefell Mountain is for braking only; the brakes are shoes applied on each side; there is no horiontal wheel or extra vehicle.
M636CI was under the impression that the braking in New Zealand relied on wheels like those used for adhesion, but I may be wrong.
Most of what I knew about the Fell system was out of Stewart's When Steam was King (otherwise notable for coverage of the infamous pound-note-puffing Garratts and "E66 and all that"). He says this about brakes:
... there were also a special number of brake vans employed on each train to assist with braking on the downward journey. These little four-wheeled vehicles, which were always called Fell vans, carried large hand-wheels inside keyed onto screwed shafts. The screws in turn caused vertical levers, to the lower ends of which were bolted cast iron blocks, to bear against the centre rail when the hand-wheel was turned. The brake blocks rarely lasted more than two trips. The engine brake gear was arranged in a different manner, but generally speaking acted the same way. Of course, after the adaptation of the conventional Westinghouse Air Brake throughout the NZR. these brakes were also in constant use in addition to the special gear
I always thought of this as transverse, with the wheel vertical and the screw axis from side to side, and the levers hinged so the blocks clamped across the center rail facing each other. That's about the only way I could see them developing enough force to wear out an iron brake block in one or two trips. I think I was right. Here are a couple of pictures of the brake gear applied to preserved Fell van F210:
There is a different angle of the same view in this contemporary description of the Rimutaka Fell operation
About the best I can do to show the actual brake lever arrangement is this finescale model chassis
Just as a note, the Fell rail looks a bit like a British bullhead rail turned on its side, supported by pedestal 'chairs' with vertical bolts through the 'web' of the rail. You can see a section of this 'in position' here (this is the preserved display of the remaining Rimutaka Fell locomotive)
I posted to the original News Wire item but the lack of ability to edit the post meant that it wasn't as clear as I'd like....
The Fell system was best known in New Zealand, where it was used on the grade at Rimutaka, north of Wellington on the North Island on the original New Zealand Railways line north. There was an easier line run by a private company (the Wellington and Manwatu Railway) on the West Coast of the North Island.
But a lot of traffic ran on the NZR line and trains had to be hauled by small 0-4-2 rack tank locomotives, class H built by Avonside in England. These had horizontal spring loaded driving wheels (as described above) driven by a separate engine on the locomotive (something like a booster, or a rack drive engine).
A normal passenger or freight train had to have four of the Fell tank locomotives with three spaced back through the train, so apart from the slow climb, there was a lot of making up and breaking down of trains at each end.
The original locomotives lasted from the 1880s until the 1950s (there are photos of the 1954 Royal Train on the incline) but the Fell section was bypassed later by spiral tunnels.
The Fell rail was also used for braking at Rimutaka and special Fell brake vans were used on trains descending the incline.
By the 1940s, diesel railcars with Fell brakes were used for passenger service, avoiding the use of the Fell locomotives for most passenger trains.
There was also a line on the West Coast of the South Island which used the Fell system for braking only. The locomotives had notched pilots to clear the Fell rail and Fell brake vans were used. The Fell system was not used on the main "trans-Alpine" main line which had a long electrified tunnel at the summit, however.
I was under the impression that the braking in New Zealand relied on wheels like those used for adhesion, but I may be wrong.
The Fell system 'works' like a cog system in that wheels that drive on the center rail assist with moving the train upgrade. Instead of using gear teeth vertically or horizontally, the Fell system has two wheels that are forced against each other by powerful springs, with the 'heads' of the rail clamped between them. This provides both the 'tractive adhesion' and some safety against derailment (as the wheels have a 'bottom' flange and cannot easily 'climb' over the railhead profile against the spring pressure). The system is relatively tolerant of 'slop' in the line and surface of that center rail, compared to many rack or pin track systems, and wear does not compromise either safety or smoothness of operation...
The Fell railway in New Zealand also used the cenre rail for traction via an auxilary engine under the locomotive.
The Snaefell Mountain Ry is 3'-6" gauge, 550V DC trolley wire, cars equipped with unusual hoop contactors, original electrical equipment replaced by post-WWII Achen, Germany, tram electrical equipment, connects at Laxey, a midpoint on the three-foot gauge, trolley wire Manx Electric Railway, runng from Douglass to Ramsey, also with original equipment including elecdtricals and mechanicals. Laxey has one dual-gauge siding. Terrific scenery on both lines.
The news wire is in error. The Fell system is not a cog system. The Fell System is a raised center rail between the two running rails. Heavy braking si done with shoes pressing toward each other from each side/
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