Engineering Wonders of the World
Volume I

 THE HEDJAZ RAILWAY. 347 by floods. Where exceptionally heavy work was found to be necessary, a temporary bridge was built to carry material for the stretch of line ahead, which was laid while the permanent bridge was constructed behind TURKISH SOLDIERS BUILDING MO- AZAMMA STATION AT AN OASIS IN THE ARABIAN DESERT. it. Consequently railhead ad- vanced uninterruptedly. For the stone arch bridges ample supplies of material were usually found close to the site, or could be brought up easily by train. Stone was used also for the stations, which have no raised plat- forms, but merely paved areas on both sides of the track. The engines used on this line are necessarily of a very powerful type, as they have to haul 250-ton trains up long grades and round sharp curves. The most notable locomotives are those Rolling 0£ articulated compound of Mallet pattern, such as have the Line. been introduced recently upon several European and American systems. The engines have very large boiler capacity, a heating surface of 1,780 square feet, and a grate area of 27 square feet. As the rails are somewhat light, the engine’s weight is distri- buted over six pairs of wheels, grouped into two sets of three pairs each. The wheels of the rear group are coupled together and placed in the main frame, and driven by two high-pressure cylinders. The second and third pairs of the front group are also coupled, and driven by low-pressure cylinders fed from the high pressure. Since the forward six wheels are mounted in a pivoted bogie truck, the engine, despite its wheel base of 28 feet, is able to negotiate with safety curves of 300-foot radius at high speed. The design of the Hedjaz locomotives OFFICIAL OPENING OF THE TEBUK STATION. Notice the substantial character of the buildings, and the wind-pumping plant. includes several other features rendered neces- sary by the peculiar characteristics of the line. Among these is the provision of un- usually large tenders, able to carry five tons of coal and 4,000 gallons of water—this last obtainable, as we have noticed already, at very few places on the railway. In fact,