Given the relative lightweight trough support structure – can track gauge be maintained without any gauge ties?
The trough weighs the same as the rail per metre length. The lateral wheel forces of tramcars (or heavy rail) are less than 10% of the vertical forces. The lateral force from one wheel is distributed along the trough side 180mm deep and a length of about 2000mm, at a pressure several orders of magnitude less than the stiffness of flexible pavements. The troughs are very stiff in both vertical and horizontal planes. The rigidity of the pavement keeps the troughs to gauge and so the rails. Where a flexible pavement is failing, eg. by plastic deformation, and there is no plan to relay, on curves there is a stainless steel strop on which the troughs sit to maintain gauge (every 3000mm). This requires a slot to be cut between rail trenches. The better solution (for everyone) is relaying that length of road and NOT using gauging bars. NB Most tube stations in London have rails not linked by gauge bars or sleepers. For over 100 years the suicide pit has not been a problem for gauge maintnance
