Anyone know anything about California Crossings. These were seen on an NCB training film from the late 1950's shot at Ashton Moss, in the Trevithick Society Holmans archive. Basically a portable tram crossing system, used to ensure very rapid positioning & removal of trams for loading on a double track heading using two Eimco rocker shovels. As the face advanced the Eimcos were used to drag the California crossing forward.

Did these originate from California or were they just a UK bit of kit (Googling the term comes up with various place names, but nothing I found giving anything about the mining term).

The main use that I saw them being used for was at pit bottoms. When you had two tracks bringing coal out to a shaft that had two cages winding coal they would usually have tubs waiting on both tracks for winding. They would usually wind up the coal from just one track to clear it for the next journey of full tubs coming out. Then they would start on the other side. By having a California crossing facing the cages you could send full tubs to either cage from either track.

my experience of them was in the 80s working on tbm tunnelling in London. They were sectional crossings attached to the last sledge of the tbm train by drag ropes ( wire bonds that is ) about 50m long.

As the tbm advanced the California would be dragged along behind it, the entry and exit ramps had slider rails which slotted over the track so that trains could run up and down

The crossing had continuous steel strakes both sides about 6" above the deck, these ran under steel pins inserted into pre-drilled holes in the lining rings on either side. This prevented the crossing tilting as it was dragged along, especially with an unloaded train on one side - there would only ever be one train, the other one would be under the belt and go straight out.

The system was that loaded trains had right of way and would go straight out to the pit bottom; as a loaded train passed the trains on the fixed crossings ( this might be in tunnels from abour 1500m up to 5km in length ) each train would advance to the next crossing and wait for the next outbound train.

an outbound train arriving at an empty crossing would wait for the next inbound, because a crossing with no waiting inbound meant a delay of some sort.

California crossings might be dragged round long, shallow radius curves by opening the bolts on one side, but they would be dropped and pulled forwards later for sharper curves

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The system was that loaded trains had right of way and would go straight out to the pit bottom; as a loaded train passed the trains on the fixed crossings (this might be in tunnels from abour 1500m up to 5km in length ) each train would advance to the next crossing and wait for the next outbound train.

That's where I remember them from too, the bacon butties were always cold on dayshift by the time the inbound train got to the TBM, especially when we were over 4km from pit bottom. Thank feck for the microwave on the back of the transformer 😉

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