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DiscussionThe Chairman (Mr J. H. Jellett) said that the Paper described some very careful planning of work which had to be carried out under difficult traffic conditions. 106. Had there been any compelling reason for adopting a 13-ft-6-in.-gauge crane track on a SO-ft-wide quay? At Southampton tracks up to 18-ft gauge were used on narrower quays with resultant lower wheel loadings, and benefit to the necessary foundation work. It was possible that the P.L.A. used the 13-ft-6-in. gauge in more restricted sites and had adopted it in the interests of standardization. 107.He felt sceptical about the suggestion that the 200-ft-span shed had cost little more than if it had been constructed in two spans of 100 ft. At Southampton research into the cost of shed construction had shown that whatever might be gained by eliminating columns in sheds was reflected in greater initial cost. Their traffic operators were very keen on having no obstructions in the shed, and the magnificent structure now being discussed offered opportunity for interesting research. Why not cost the cargo operations for a year and then compare them with the cost of operations conducted in the shed after dummy columns had been erected? Such columns ought not to be so slight as to be brushed out of the way by the traffic, and would need to be sufficiently like the real thing to impose the necessary traffic pattern. This would settle once and for all the question whether the cost of eliminating columns in transit sheds was really justified in operation.108. It was stated that mobile cranes would not be permitted to work inside the shed. Why, then, had 20 ft clear minimum head room been provided? Traffic operators were unwilling to stack up to the limit of the headroom and this had an unhappy effect on the capacity of the shed.109. If cranes were not to enter the shed, what necessity was there for the expensive 2o-ft X B-ft doors? How manual would their operation be? Experience had shown that doors of that size, if intended for manual operation, were usually in the end operated with the assistance of electric trucks, the latter exerting pressure in places not intended by the engineer. Were the doors to be operated by a mechanical device of any kind, such as windlassing, to ensure that the manual effort was supplemented?110. At Southampton, also, fibreglass had been used in roofs. Fortunately it had not yet become the subject of fire regulations, and he hoped that such regulations would not be so framed as to prevent the use that had already been made of fibreglass. ~~ ~ ~~ t Proc. Instn civ. Engrs, vol. 15, p. 411 (April 1960). l Downloaded by [] on [11/09/16].