Photo © Jim Shead

Locks are an essential feature of any canal which needs to gain or lose height. The lock flight at Foxton was built in 1810 and a boat taken through the ten locks takes about 45 minutes to climb the 75 ft hill. 

For economic reasons the locks at Foxton were built only 7ft wide to take "narrow boats" as water supply was restricted. There's little room to manoeuvre, although a Passing Pound exists halfway down to allow boats travelling in opposite directions to pass. 

It's all economically planned too. To climb the 75 ft hill it was decided to build a "staircase", where the top gates of one lock are the bottom gates of the next, with ponds alongside. The 45 minutes to negotiate it includes using 25,000 gallons (113,650 litres) of water per passage. All of the water passes from lock to side pond as it goes down the hill. The use of the side ponds saves considerable amounts of water compared to conventional staircase locks. The water from descending boats is stored in the side ponds for the use of ascending boats. If one boat goes down, and one up, passing in the middle, they share a lock full of water. 

There's also a museum with a working replica of the 'Incline Plane' that pulled up 4 boats at a time in just ten minutes. Unfortunately it ceased to operate in 1911 after facing tough competition from the railways in the carrying of coal. The locks are quite spectacular and a remarkable piece of engineering. The cycle route passes so close to the locks that it's worth the few minutes detour.