THE CRANE IS a tributary of the River Thames. Named after Cranford (Middlesex) through which it flows it is about 8 ½ miles in length. It rises as Yeading Brook and flows towards its mouth at Isleworth, just opposite the southern tip if Isleworth Ait. On its way, the Crane passes east of Heathrow Airport, Hounslow Heath, Whitton, Twickenham, and St Margarets. It also feeds the man-made Duke of Northumberland’s River, which enters the Thames about 610 yards downstream from the mouth of the Crane.

The Crane flows through beautiful, wooded parkland known as Crane Park. This incredibly peaceful open space, part of which is a nature reserve, is in Whitton near Twickenham. Part of the park is in the Borough of Richmond-on-Thames and the rest in the Borough of Hounslow. The Crane, which contains a wooded island and breaks up into rivulets occasionally, is bordered on both sides by the park. The island, Crane Park Island, now a lovely nature reserve, a peaceful oasis in a busy part of London, was created for a purpose that was far from peaceful: warfare.

In the 1760s, a gunpowder works was established in what is now the west part of Crane Park. The island was created to form a millstream for operating a waterwheel connected to a mill for grinding saltpetre (nitrates of either sodium, potassium, or calcium) used to make gunpowder. It was part of a complex of buildings that housed the Hounslow Powder Mills. Before the 19^th century, what is now Crane Park would have been part of the then much vaster Hounslow Heath. The website of the Twickenham Museum noted that gunpowder mills were established on the Heath as early as during the reign of King Henry VIII.  

All that remains of the Hounslow Powder Mills is a tall brick tower topped with a lead roof and a small lantern with a weathervane. It resembles a lighthouse. This was built either late in the 18^th century or early in the 19^th. Lying near it are a couple of circular millstones, which might have been used for grinding gunpowder. Described by some as a shot tower, it might have been used to manufacture lead shot. Molten lead would have been poured through a copper mesh near the top of the tower, and as it fell downwards, it formed into droplets, which when cooled became pellets of lead shot. This is most likely, but others suggest that the tower was part of a windmill.

Manufacturing gunpowder was a hazardous procedure, and unintended explosions were not unusual. The Twickenham Museum’s website related:

“Joseph Farington noted in his diary on Monday 25 January 1796 that: “The Powder Mills at Hounslow were blown yesterday. The concussion was so great as to break the windows in the town of Hounslow. Hoppner having been to Eaton, on his return rode to the spot where the Mills had stood, not a fragment of them remained. They were scattered over the country in small pieces. Three men were killed”… Burial records note deaths from further explosions: 5 on 17 November, 1 on 19 June 1798, 7 0n 15 July 1799, 2 on 27 June 1801, and so on through the century. Abraham Slade noted in his diary for 1859 that: “On the 29 of March the Powder Mills blew up, sending 7 poor souls into eternity in a moment. It has broken a great deal of glass in Twickenham & neighbourhood. We thought the whole place was coming down.””

The last major explosion at the Hounslow Mill was in 1915.

The powder mills passed through the hands of various operating companies: Edmund Hill, John Butts and Harvey and Grueber until 1820, then Curtis and Harvey until 1920, and then by Nobel Industries.The licence for producing explosives at Hounslow Powder Mill was revoked in 1927. In 1927, a Twickenham councillor, Frank Yates, bought the site. Later, he sold part of it for housing and the rest to Twickenham Council, who used it to create what is now Crane Park.

In addition to the impressive tower and a rusting sluice gate, several other less impressive remnants of the manufacturing complex can be seen on the island in the form of the bases of engine housings: lumps of bricks and concrete with thick metal rods protruding from them. Apart from the tower and a few other barely identifiable remnants, it is hard to believe that the sylvan and peaceful Crane Park was ever a place where the material of warfare had been produced for several centuries.