180 RECENT DEVELOPMENTS IN SHIPYARD PLANTS. 



eludes not only the shipfitters' shop, but also the forge shop and boiler shop, and may 

 later include the sheet metal and pipe shops. The shipfitters' shop in each of these 

 cases consists of two bays, one for plate work and one for angle work, each loo feet 

 wide and 700 feet long, a mould loft being provided over the angle bay of the full 

 size of that shop. The under side of the floor of the mould loft and of the roof 

 trusses of the plate shop is at a height of 45 feet above the shop level, and the 

 height of mould loft from floor to roof trusses is 9 feet. The plate and angle shops 

 are provided with three tiers of cranes, the upper tier spanning the full width of 

 each bay, having 15 tons capacity, and providing for a total lift of 30 tons; the 

 second tier consisting of traveling jib cranes of 3 and 5 tons capacity at reaches 

 of 30 and 20 feet with a hook height of 25 feet. The lower tier consists of special 

 cranes intended to carry yoke riveters and smaller portable tools. For these last 

 cranes electric motors for travel are provided with a swinging boom and a chain 

 hoist to facilitate the handling of such tools. The lower tier of cranes will extend 

 for about a third of the length of the shop at the outgoing end, as they are intended 

 primarily for work in connection with assembling and riveting. 



Structural material is to be stowed on the principle followed by many of the 

 bridge builders, a series of bridge cranes operating on runways extending across the 

 incoming end of the shop. This stowage space will provide an area of approximately 

 160,000 square feet, consisting of four bays served by bridge cranes with 80-foot 

 spans, and the area will eventually be roofed over. It is proposed to deliver mate- 

 rial into the stowage space by standard gauge tracks, and to deliver into the bays of 

 the shop by narrow gauge tracks. It is not expected that 160,000 square feet will 

 give the full stowage area required for building and repair work for the largest 

 yards, and further provision will be made for a reserve stowage in a less central 

 location. Continuous flow of work is to be obtained by the raw material entering at 

 the end of the shop adjacent to the stowage yard going first to the laying-ofif space, 

 then to the fabricating area and thence to the assembly space and out at the oppo- 

 site end of the shop, delivery from the shop to the building slips being by means of 

 standard gauge tracks. With this arrangement, a piece of material may be delivered 

 from any point in the shop to any ship under construction with a maximum of three 

 moves, the first from its position in the shop to a car by means of a bridge crane, the 

 second by the transfer of the car under the slip, and third, from the car to the loca- 

 tion desired on the ship by a bridge crane. There is no combination of shop bays 

 and building slips, where there is more than one of each, that can accomplish this 

 transfer with less than three moves. 



The size of plates used in ship construction has grown steadily, and an effort has 

 been made in laying out these shops to adopt as the maximum size that we are likely 

 to come to, a plate 36 feet long by 8 feet wide, and to provide machine tools and ar- 

 rangements so that any increase in size up to this point may be taken care of with- 

 out the discarding of the present outfit or its rearrangement. In comparatively re- 

 cent years we have gone successively through the stages of equipping for 24-foot, 

 28-foot, 30-foot and 36- foot plates. The cost of equipment, especially rolls, increases 



