so as to better able to get to the scene of an accident. They are much more mobile, and are able to manoeuvre around an accident scene, better than a crane only limited to rail access. In the United States the advent of contractors to cleanup and re-rail a line to productive status came in around the late 1970s and early 1980s. The use of caterpillar tractor mounted sidebooms (pipelayers) enabled the contractors to mobilize around a site without having the need for crane mats and multiple lifting locations. In the 1990s a new generation of railway cranes was developed. While the conventional diesel hydraulic road cranes were adopted with some small trolleys to move on the rail track, the new generation had a professional high speed railway chassis for up to . The superstructure is also diesel hydraulic with telescopic boom and counterweight and designed to the railway's specific needs. These cranes can travel with suspended loads and keep levelled even on an elevated track, due to the automatic cant compensation. It is possible to work on one outrigger only, work with boom in horizontal position under bridges or under the overhead wires. Capacities are as high as 200 tonnes. It makes this new generation useful for maintenance work and switch and crossing renewal, as well as recovery work. Manufacturers Germany Deutsche Maschinenbau-Aktiengesellschaft Kirow Ardelt GmbH Krupp Ardelt Leo Gottwald KG Great Britain Cowans, Sheldon & Company, Carlisle – cranes are labelled Cowans Sheldon Ransomes & Rapier Thomas Smith & Sons (Rodley) Ltd – cranes are labelled Smith Rodley (not "Smith & Rodley") Taylor & Hubbard Ltd, Leicester Appleby Brothers Craven Brothers Ltd. Stothert & Pitt United States American Hoist and Derrick Arva Industries Badger Equipment Company Bucyrus Industrial Brownhoist Link-Belt Lima Little Giant Corporation Marion Ohio Railroad Crane Swingmaster Corporation Cullen Friestedt Co (Burro), numerous successor companies later owned Burro Russia Kambarka Engineering Works JSC "Kirovsky mashzavod 1 Maya" Preservation Most heritage railways in the UK have one or more preserved railway cranes, either just as historic exhibits, or as fully functioning examples assisting with the operation of the railway. Although not normally required for re-railing activities, they are exceptionally useful for track relaying and the restoration of locomotives and rolling stock, and help to avoid expenditure on outside contractors. Three cranes of various sizes are preserved at the Western Pacific Railroad Museum at Portola, California. They are