Thames Lock was originally built in 1805 to deal with difficulties arising from the tidal Thames and became a well known bottleneck before being enlarged and mechanised in 1962. You initially pass a collection of unattractive houseboats at Ham Wharf and the narrow towpath to Brentford Gauging Lock isn’t the best. Nearby was Brentford Dock, once a mass of Great Western Railway sidings and wharfs transferring goods that had been brought from the Thames, is now a housing estate with run down industrial units. On the other side of the river is Johnson's Island, an artistic and boat building community.
Brentford has its origins as a crossing over the River Brent and the road bridge near the gauging lock was the scene of a Civil War battle in 1642 preventing the King from entering London. A huge variety of goods passed through the lock that was duplicated in 1900 and the hundred year old Toll House marks the start of the non-tidal waterway. A sign tells the Grand Union traveller that they have 93 miles to Braunston and 137 to Birmingham.
From underneath a large run down British Waterways shed, you pass GlaxoSmithKline whose glass offices and works of art make a statement regarding their pre-eminence in the 21st century business world. Further on, there’s a boat graveyard next to Clitheroes Lock 99. Nearby is Boston Manor, one of the ancient manors of Middlesex, the early 17th century manor house still stands in Boston Manor Park.
The 18th century canal then meets the 20th in the guise of the M4 before going under the Piccadilly Line and the motorway to reach Osterley Lock. Before the railway you have to cross the listed 1820 Gallows Bridge constructed by Horseley, the famous Black Country iron founders.
On your way to Hanwell Locks there’s an odd memorial to a British Waterways Pile Driving Competition in 1959 and, just before the locks, the Grand Union throws off its split personality by leaving the River Brent. There are six locks that raise the Grand Union Canal by just over 53 feet. Near Lock 94, goods went through what is now a bricked up archway to the other side of a rather impressive wall but nothing was allowed out, as behind the wall was Hanwell Lunatic Asylum – allegedly the first purpose built institution of its type in the country opened in 1831. Also look out for the steps allowing horses who may have fallen into the canal to get out more easily.
Isambard Kingdom Brunel's first and last undertakings are both close by. The nearby Wharncliffe Viaduct was his first major structural design and the first railway viaduct to be built with hollow piers, which have now been colonized by bats. And, before the top lock you pass Three Bridges, his last major undertaking in 1859, where the problem of taking the railway under the canal to Brentford Dock was solved by placing the canal in a cast iron trough, with Windmill Lane going above them both.
The canal continues towards Southall where the swans dine on naan bread rather than Mother’s Pride. Southall once boasted one of the world’s largest margarine manufacturing plants. Established in 1894 by a Danish margarine magnate, it produced 800 tonnes of the stuff each week and was so large a branch canal (the Maypole branch above Norwood Top Lock) was demanded to carry coconut oil to the factory. It closed in the 1970s after being transformed into a sausage factory
Once past Norwood Locks 91 and 90 and the Havelock Road arm, much of what you see is rather tediously residential. It is a community with no connexion with the waterway and clearly the residents use the canal as a dumping opportunity rather than an amenity. Here the banks are littered with detritus and local people don’t seem to adhere to the notices advising them not to throw foodstuffs into the canal.
The long straight ends as you cross over the bridge at the BW maintenance depot at Adelaide Dock. Round the corner, opposite a winding hole, is the Old Oak Tree pub and then further on by bridge 201 is the Grand Junction Arms. The semis now give way to cottages and factories before a row of houseboats and a Tesco supermarket which occupy the former Grand Union Canal Carrying Company's extensive maintenance facilties, moorings and control office at Bull's Bridge.
