Direction of travel over points

[Wellwhynot]

Is there a preferred direction of travel over points or should a loco be happy to pass over from any direction 

[JJ73]

It shouldn't really make any differance what way!!!  😀

[Ruffnut Thorston]

The key thing is that if travelling through points in the "trailing" direction, they should be set for the direction you are coming from to avoid any problems, like derailments, and electrical short circuits, etc.

 

If travelling in the "facing" direction, the points should be set for the route that you want to take. No other problem than your loco could go the wrong way. 😉

[walkingthedog]

Points are crossed in any direction particularly  in sidings.

[LCDR]

Facing direction - passing through the points (AKA turnout) where the locomotive reaches the moveable switch blades before the crossing where the routes intersect

 

Trailing direction - passing through the turnout where the locomotive reaches the crossing before passing through the switches.

 

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The situation on the real railway -

On passenger lines facing points have to be fitted with locks to prevent them being operated as the train is going over and causing a derailment. This has been a legal requirement for over 140 years.

 

Very serious derailments used to occur in the early days of railways before proper locks were provided where points crept open as the train passed over . The fear of this happening therefore meant that railway companies avoided putting facing points in passenger running lines unless absolutely essential. Crossovers at stations between one line and another were usually trailing crossovers, and connections to sidings also were arranged to be trailing for normal movements along the main line. This became a convention which lasted until very recent times. 

 

In fact trailing connections into sidings did make working them easier. A goods train with wagons to attach and detach would leave the brakevan just before the connection, draw forward and propel the train into the siding. The wagons going away would be attached, pulled out of the siding on to the main line and then pushed back on to the brake van and secured. The train would then draw forward with the wagons to be left behind and propel them into the siding where they could be placed for loading or unloading. The locomotive would then return to the wagons waiting on the main line, attach them, and set away in its journey. 

 

On goods only lines and in sidings locking is not a requirement. Because passenger line points are locked they can be damaged if a train passes through them in the trailing direction so the signalman is prevented from clearing any signal for a movement over them by interlocking as too is any movement in the facing direction. 

 

Facing point locks in mechanically signalled location is provided by a thick steel bar which fits tightly into a hole in the locking tie bar .

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In sidings however, and at a few junctions where only trailing moves will be made, hand operated points which are held in position by powerful springs will be provided. These can be set in either position for facing moves but can be 'trailed' through without being set, the locomotive wheels push the point blades over against the spring.  The point blade springs should work on the over centre principle so that they should remain in the position they have been pushed to until the lever is operated again.  Unfortunately worn or defective springs can bounce back, and so shunters and engine men were constantly reminded to check that the points were set right before any facing move was made.

 

For passenger moves in an emergency over points which were not fitted with locks a set of devices were provided to hold the point blades safely in position. These consisted of a wooden wedge to be pushed into the  open side, and a clamp which was to be fixed to the closed side which when screwed up tight held the blade tight agaist the stock rail.  The clamp would then be padlocked to stop anyone interefering with it. The process of doing this was know as Clipping and Padlocking.