burrowing junction

burrowing junction (plural burrowing junctions)

(rail transport) A junction where the diverging line descends to a level where it can pass under the main line, the purpose being the avoidance of conflicting movements.
- 1962 December, “Beyond the Channel: Switzerland: Transformation at Zurich”, in Modern Railways, page 417:
  The latter and the Basle-Gotthard freight traffic will both pass through Othmarsingen, but an additional line here and a burrowing junction will keep the Gotthard freights clear.

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