sea. The New Cut, a canal south of the river, was built as part of the drainage works, joining the river again at the sea sluice. The canal was used to transport the thatch crop inland by barge, its bridges being built particularly high to enable the bulky cargo to pass beneath. The drainage was improved after 1846 using steam-powered pumps. These were made by Richard Garrett & Sons of the Leiston Iron Works. There were four windmill sites on the levels. The Eastbridge Windpump was a smock mill built in the mid-19th century, probably by the millwright Robert Martin of Beccles. It stood north of the New Cut. The mill worked a three throw pump with square pistons. The windpump was working until 1939 and collapsed in February 1977. The remains were rescued by the Suffolk Mills Group in July 1977 and the mill was rebuilt at the Museum of East Anglian Life in Stowmarket in the early 1980s. The Sea Wall Mill stood north of the New Cut but closer to the coast than the Eastbridge Windpump. It was a smock mill built in the early 19th century. The mill worked by wind until it was tailwinded in January 1935, breaking the windshaft and rendering the mill sail-less. The scoopwheel was subsequently worked by a Hupmobile petrol engine, and later by a diesel engine. The mill collapsed in the summer of 1976. A third smock mill stood south of the New Cut and seaward of the ruins of the chapel. Built by the millwright Collins of Melton, it was blown down in the 1920s and a Titt windpump was erected on the site to drive the scoopwheel. This windpump had sails diameter. Another Titt windpump, with sails diameter stood 1.6 km (a mile) south of this. Both Titt windpumps were standing in 1938. The levels were re-flooded during World War II to defend against invasion along the East Anglian coast. Military defences were built at Minsmere and neighbouring Dunwich, including pillboxes, anti-aircraft defences, anti-tank blocks and barbed wire defence lines. The Army also used much of the heathland for military manoeuvres, including preparations for the invasion of continental Europe. Before the war, the Ogilvie family had owned and managed the area as farmland and as a shooting estate, planting many deciduous trees as part of their hunting management plan. After the war, they decided to leave the marshes