Re: inside running rail of the curve will be accompanied by an addition guard rail
Dennis, as usual, shares interesting information. Enough so that I went back to the Cyc., which mentioned the repositioning of the low (inner) side guard rail relative to the high side running rail (the gauge between the guard and opposite rail being 4’ 6 3/4”). It goes on to say for sharper curves, a guard rail may be applied to the inside of the high side rail, with the same relative gauging.toggle quoted messageShow quoted text
For the sharpest curves, a third guard rail may be applied to the inside of the low side rail - this one to support overhanging blind driver tires.
All of the pictured applications used lighter rail for the guard rail, with special chairs that both braced the guard rail and raised guard railhead's height to the the same plane as the running rail. They also allowed the base of the guard rail to overlap the base of the running rail - no shearing required in that case. One additional guard rail implementation called for the guard rail to be laid on it’s side to take advantage of increased section strength (deeper girder) and plenty of meat in the sideways railhead to accommodate wear.
All of these descriptions had a caveat that all guard rail use was considered objectionable due to increased costs (material and maintenance), so should be used only in special cases.
On Jul 24, 2020, at 2:15 PM, Dennis Storzek <destorzek@...> wrote:
On Thu, Jul 23, 2020 at 09:02 PM, Jim and Barbara van Gaasbeek wrote:
There may be other reasons why the HTC could get away with such absurd track radii without guard rails.There was... the size of their motive power. Freight cars of this era were fine with those tight curves, and the Harlem Transfer used a boxcab diesel with trucks that were hardly any longer wheelbase. Even before the diesel the motive power was a tiny 0-4-0. But mainline railroads tended to use larger power for local switching; six couple and smaller eight couple power being common. These long rigid wheelbases had problems with tight curves. The first modification needed was to widen the gauge... as much as 1-1/2 or even two inches, and this has been done. How can I tell? The standard flangeway for guarded curves on 4'-8 1/8" gauge track is just under 2". This is so small that it is not obtainable with standard rail' the bases interfere with each other and the base of the guard rail needs to be sheared. However, when the gauge is widened the guard rail moves in tandem with the opposite running rail. The photos presented have the guard rail so far from the running rail that there is room for spikes in between. The gauge has been widened at least 1-1/2" to accommodate steam locomotives.