| rdfs:comment | - Based in Letchworth, Hertfordshire in England, SD was started in 1922 by Harry Shelvoke and James Drewry, both of whom had successful careers in commercial vehicle design and manufacture with Lacre Lorries. During the Second World War, like most British manufacturing companies, S&D's entire output was devoted to the war effort, producing aircraft parts, equipment for landing craft and tanks, and even a miniature submarine (the Welfreighter) at their Letchworth plant. The W-type of the 1950s originally had a SD 3.9 litre petrol (gasoline) engine but latter had a Perkins P4 series diesel.
|
| abstract | - Based in Letchworth, Hertfordshire in England, SD was started in 1922 by Harry Shelvoke and James Drewry, both of whom had successful careers in commercial vehicle design and manufacture with Lacre Lorries. Its first product was the "Freighter", originally a multi-purpose flatbed truck notable for its tiny wheels and tiller-type steering, but it was soon adapted for refuse collection. SD built the Latil timber tractor under license in the UK from Latil of France. SD soon became an established innovator in the field of refuse collection vehicle design, producing vehicles such as the Fore and Aft Tipper, which used a pivoting body to redistribute the load, and the Revopak of the 1970s which used a huge revolving fork to mutilate and compact refuse. During the Second World War, like most British manufacturing companies, S&D's entire output was devoted to the war effort, producing aircraft parts, equipment for landing craft and tanks, and even a miniature submarine (the Welfreighter) at their Letchworth plant. The W-type of the 1950s originally had a SD 3.9 litre petrol (gasoline) engine but latter had a Perkins P4 series diesel. The 1960s saw the introduction of the larger TW-type, with a Perkins P6 series diesel, or a SD gasoline engine. This truck grossed 11 tons. The TY-type was introduced in 1963 with a glassfibre cab, and a Leyland ).350 engine, at a gross weight of 14 tons. In the late 1970s, SD went head-to-head with its arch-rival Dennis, and began manufacturing fire engines through its newly-established Special Purpose Vehicles (SPV) division. In the 1980s, SD became part of the Dempster Brothers company of the United States, and continued to trade, under the name "Shelvoke Dempster", through the 1980s, although its product range diversified further into front-end loading dustcarts (based on Dempster's ubiquitous "Dumpster" system), as well as a licence-built version of Dempster's "Routechief" rear loading refuse body. The company was however plunging deeper into a financial crisis, and by the end of the 1980s, Dempster had pulled out. The remainder of the company was then absorbed into Dennis, and the "Dennis-Shelvoke" name continued briefly, but the company was effectively dead by 1992. SD's demise was attributed to a number of factors - for instance the deregulation of waste collection in the 1980s meant that many municipal authorities subcontracted this activity out to private companies. SD's vehicles had traditionally been considerably more expensive than those of their competitors (largely due to their hand-built aluminium bodywork) and cost-conscious councils soon started investing in cheaper foreign vehicles. SD had also spent huge amounts trying to make money on the SPV venture, and fought an increasingly futile battle with Dennis. SD tenaciously stuck with their Revopak continuous loading system for waste collection vehicles, which, although effective, was more expensive to operate due to higher fuel consumption, and authorities looked for cost-saving intermittent-loading dustcarts instead. Dennis launched their "Phoenix" range of sweep/slide style refuse compactor dustcarts in 1979, which, with their lower operating costs, quickly eroded SD's market share. Despite the closing of the company, many hundreds of SD vehicles are still in service. For example, many fire engines are used at small provincial airports, and many developing countries use second-hand ex-British refuse collection vehicles, most notably on the island of Malta.
|
