Given Perovsky's failure in 1839 Russia decided on a slow but sure approach. In 1847 Captain Schultz built Raimsk in the Syr delta. It was soon moved upriver to Kazalinsk. Both places were also called Fort Aralsk. Raiders from Khiva and Kokand attacked the local Kazakhs near the fort and were driven off by the Russians. Three sailing ships were built at Orenburg, disassembled, carried across to steppe and rebuilt. They were used to map the lake. In 1852/3 two steamers were carried in pieces from Sweden and launched on the Aral Sea. The local saxaul proving impractical, they had to be fueled with anthracite brought from the Don. At other times a steamer would tow a barge-load of saxaul and periodically stop to reload fuel. The Syr proved to be shallow, full of sand bars and difficult to navigate during the spring flood.