GREAT EASTERN. 



501 



GREAT EASTERN, STEAMSHIP, the acci- 

 dent to and repairs of. On the 27th of August 

 the Great Eastern, while hove to the propeller 

 engines being in motion ahead and the paddle 

 engines in motion aback, waiting for a pilot, 

 came in collision with a submerged rock near 

 the east end of Long Island. A large fracture 

 was made in her outer skin, and a considerable 

 list or careening took place from the entrance 

 of the water between her skins, but the inner 

 one being uninjured, she was brought to her 

 anchorage near the city of Xew York. Her 

 passengers, some without any knowledge of the 

 accident, and her entire cargo, were discharged 

 within ten days, without injury to a single ar- 

 ticle. The agents of the ship, Messrs. Howland 

 and AspinwalL, called the engineers, Messrs. H. 

 B. and E. S. Renwick, into consultation with 

 Capt. Paton of the ship, and as there were no 

 docks in the country of sufficient capacity to 

 admit or lift her, it was decided to repair the' 

 injury by means of a caisson or scow, as in figs. 

 1, % 2, with two entrance shafts extending from 

 one of its sides upward a little above the sur- 

 face of the water. To determine the form of 

 the vessel at the fracture, in order to fit the 

 gunwales of the caisson to it, the engineers 

 proposed a species of adjustable template 

 composed of a frame of timber of the same 

 size as the intended gunwale of the scow, 

 and having a series of sliding bars like fence 

 pickets arranged around 'it, which could be 

 moved perpendicularly to the plane of its sur- 

 face to any desired positions. The frame was 



to be ballasted sufficiently to sink it and to 

 be drawn by ropes against the ship, at the 

 place where the caisson was to be fitted. Then 

 a diver was to be sent down to shove the bars 

 toward the ship until their ends touched it and 

 secure them by nails, so that when the frame 

 was drawn up the points would present An ex- 

 act counterpart of the ship. The only difficulty 

 was that the whole work depended on the skill 

 of the diver, and it was finally decided to take 

 the moulds from the inner skin, which was sup- 

 posed to be parallel with the outer one. To do 

 this 600 tons of coal were moved from the bun- 

 kers over the fracture, to the opposite side of 

 the ship. While these moulds were being taken 

 inside the ship, the divers were busy on the out- 

 side, determining the exact size and position of 

 the fracture, of which preliminary examinations 

 had already been made, and also in surveying 

 the bottom to see if other fractures existed. The 

 ship was undergirded by a chain drawn tight be- 

 neath the bulkhead immediately aft the screw 

 engines, the first bulkhead aft the fracture, and 

 the inside moulds were referred to the same 

 bulkhead. The length of the fracture and its 

 distance forward from the chain were now meas- 

 ured by the divers with a line. As only each 

 outside strake of the plating at the side of the 

 ship was connected with the inner skin by a lon- 

 gitudinal partition, it was deemed necessary to 

 locate the port gunwale of the caisson upon an 

 outside strake where the pressure against the 

 ship would be best sustained. On this account 

 it became not only necessary to determine the 



FIG. 1. 



widths of the fracture, but also its position in 

 reference to the strakes. The base for these 

 measurements was the termination or line of the 

 salmon colored strakes. This line was referred 

 to the 30 ft. deck, as were also the inside moulds. 

 A line with a hook at its end was carried down 

 by the diver at every place where a measurement 

 was made ; it was hooked on to the edge of 

 every outside strake and to the side of the frac- 

 ture, drawn tight to the base line, and the dis- 

 tance noted. From the moulds taken from the in- 



side of the ship, and the measurements outside, 

 the lines of the ship were laid off on the mould- 

 ing floor of the ship yard, the form of the frac- 

 ture and indentation and the size of the caisson 

 necessary to repair the injury determined. It 

 was at first proposed to make the caisson of a 

 rectangular section, but on consultation with 

 the shipbuilder Mr. Van Deusen, it was decided 

 to make the ribs curved. Fig. 1 shows a frac- 

 tional longitudinal, and fig. 2 a cross section of 

 the caisson, as it was constructed. In order 



