Grand Union Canal Main Line - London to Braunston

The Grand Union Canal runs from the tidal river Thames at Brentford to join the Oxford Canal at Braunston.  The Grand Union Canal continues from Braunston to Birmingham.  The Canal is joined by the GU Leicester section at Norton Junction.  The main line of the canal from Brentford to Braunston is 98.5 miles (158.6 km) and has 70 locks.

There are Arms to:
Aylesbury - 6.3 miles (10.1 km) - 16 locks - joins at Marsworth Junction
Buckingham - 10.7 miles (17.2 km) - 3 locks - joins at Cosgrove Junction - mostly derelict but under restoration
Northampton - 4.8 Miles (7.7 km) - 17 locks - joins at Gayton Junction
Paddington - 13.6 miles (21.9 km) long - no locks - joins at Bulls Bridge Junction
Rickmansworth (former) Gas Works (River Chess Branch) - 0.3 miles (0.5 km) - 1 lock - joins at Batchworth Junction
Slough - 4.9 miles (7.9 km) long - no locks - joins at Cowley Peachey Junction
Wendover (under restoration, partly navigable) - 6.5 miles (10.5 km) long - 1 stop lock - joins at Bulbourne Junction

The River Nene joins the Northampton Arm in Northampton.  The Regent's Canal joins the Paddintgon Arm at Little Venice.

The maximum size of boat that navigate the main line of the Grand Union Canal (incl Paddington Arm) is
length: 79' 1" (24.1 metres) - Lock 58 Berkhamsted
beam: 12' 9" (3.88 metres) - Tiddenfoot Narrows, Leighton Buzzard
headroom: 7' 4" (2.23 metres) - Harrow Road Bridge 3
draught: 4' 1" (1.23 metres) - cill of Lock 58 Berkhamsted Lock

The Aylesbury, Buckingham, Northampton, Slough and Wendover Arms are narrow and have smaller dimensions.

The locks south of Bulls Bridge Junction require a Sanitary Station key for operation.
Locks 49 (Northchurch) to 51 (Gas Lock 1) are locked and unavailable between 9pm and 8am daily.
Lock 53 and Bridge 147 (Winkwell Swing Bridge) require a Sanitary Station key to operate.
Locks 7,9, 10, 11 and 15 on the Aylesbury Arm require a Sanitary Station key to operate.



IWA Branches

Chiltern - Tail of Stockers Lock to Ship Bridge, Marsworth; Aylesbury Arm; Wendover Arm
Middlesex - River Thames to tail of Stockers Lock; Paddington Branch west of Ha'penny Bridge;  Slough Arm
Milton Keynes - Great Ouse Aqueduct, Wolverton to Ship Bridge, Marsworth; Derelict section of Stratford/Buckingham Arm
North and East London – Paddington Branch east of Ha’penny Bridge
Northampton - Great Ouse Aqueduct to Braunston Turn; Northampton Arm

Navigation Authority

Canal & River Trust
Head Office
First Floor North
Station House
500 Elder Gate
Milton Keynes, MK9 1BB

T: 0303 040 4040
Canal & River Trust website

(Thames to Springwell Lock, Paddington Arm, Slough Arm)
1 Sheldon Square, Paddington Central, London, W2 6TT

(Springwell Lock to Braunston, Aylesbury Arm, Northampton Arm, River Chess Branch, Wendover Arm)
510-524 Elder House, Elder Gate, Central Milton Keynes, MK9 1BW