all-relay interlocking
| with
| geographical
| circuitry
| all relay interlocking | |
| railw. sec.sys. | apparato centrale a relè |
| with | |
| gen. | con |
| geographical | |
| gen. | geografico |
| circuitry | |
| el. | circuiteria |
| |||
| apparato centrale a relè | |||
|
all-relay interlocking : 4 phrases in 2 subjects |
| Communications | 1 |
| Transport | 3 |