Hall Green Branch
The Hall Green Branch of the Trent and Mersey Canal is a canal in east Cheshire, England. It runs for one mile from Kidsgrove to Hall Green, where it makes an end-on junction with the Macclesfield Canal at Hall Green Stop Lock.
At Poole Lock aqueduct, the canal crosses over the Trent and Mersey Canal main line, which it joins, after a further 0.5 miles (0.8 km), at Harding Junction. This junction is about 0.75 miles (1.2 km) from the northern portal of Harecastle Tunnel.
Hall Green Stop Lock
The stop lock at Hall Green, which has a 6-inch (15 cm) fall from the Macclesfield to the T&M, was originally built as two chambers end to end, to allow for either canal to be higher. The second chamber fell into disuse when the weir level on the top pound of the Trent and Mersey Canal was permanently lowered after nationalisation to improve the air draft in Harecastle Tunnel.
Whilst the fall of the lock may appear trivial, it cannot be taken out of use (as many stop locks have), because lowering the bottom pound of the Macclesfield Canal would lead to draft problems on it (as it is a fairly shallow canal), and raising the top pound of the Trent and Mersey would lead to air draft problems through Harecastle tunnel. Indeed, as Harecastle continues to sink, the weir level may be lowered further, leading to an increased fall at this lock.