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"Points Locked By Another Route" Examples

(A set of) Points (aka "switch" in USA) generally has a straight "through" track (such as the main-line) and a diverging route. (Singular: (a set of) points; Plural: (sets of) points). Points set to the straight-through track are said to be set "normal"; points set to diverge from the straight-through track are said to be set "reverse". See Wikipedia .

Example 1 - "Points locked normal by another route" (may be displayed as "Points locked (N) by another route"). (Bristol sim)

Fig. 1

:usertrack:points_locked_examples:points_locked_normal_1.png

A route has been set along the Down line from signal 104 to signal DB105, thus the points between them are set normal. Since the corresponding points on the Up line are interlocked with the Down line points, setting this route also sets them normal, hence the small white rectangle on the Up line which indicates that these points cannot be changed either.

Trying to set a route from 404 to DB105 results in the "Points locked normal by another route" message, since this would involve setting the points to reverse as part of the route.

Fig. 2

:usertrack:points_locked_examples:points_locked_normal_2.png

However, setting a route from 117 to 119 is permissible since the direction of the points does not need to be changed. Note that because this route also sets the nearby set of points on the Up line to normal, the interlocked points nearest signal 104 on the Goods line must also be set normal (white rectangle). Furthermore, since the overlap of this route extends to and involves the points nearest signal 119, this also causes the corresponding points on the Goods line to be set normal (white rectangle).

Fig. 3

:usertrack:points_locked_examples:points_locked_normal_3.png

Just to show that we can set a second route between 117 and 417 as this does not conflict with the setting of the first set of points (nearest 117).

Example 2 - "Points locked reverse by another route" (may be displayed as "Points locked (R) by another route"). (Bristol sim)

Fig. 1

:usertrack:points_locked_examples:points_locked_reverse_1a.png

Here we have set a route between 404 and DB105, setting both intervening sets of points to reverse. If we now attempt to set a route between 117 and 119, SimSig will display the message "Points locked reverse by another route".

Note that in the above examples, points were locked by the action of setting a route, which locked the points in the direction of the route. You may also lock points normal or reverse without having to set a route through them. See Manually swinging and locking points

Last edited by GeoffM on 15/09/2016 at 03:00