beam. She was, therefore, about 7 feet longer and 

 about 2 feet 3 inches wider than the Savannah. The 

 plan shows she was about 2 feet 4 inches deeper in 

 hold than the Savannah, and, according to Cutler, she 

 had "an unexpected degree of sophistication for a 

 coastal packet of that period." '^ By modern stand- 

 ards, the Ohio shows a well-advanced design for the 

 period. 



Reconstructing the Plans 



The first step in the reconstruction of the Savannah'?, 

 plans was to block out the register dimensions on a 

 scale of one-quarter inch to the foot in a drawing and 

 then to work out the profile, using the Ohio plan as a 

 general guide. This produced a hull about 100 feet 

 9 inches in length at main rail to inside of plank, or 

 "moulded"; 25 feet 6 inches moulded beam, allowing 

 3 inches for plank (as usual in a ship of this size and 

 date); and about 15 feet 4 inches moulded depth at 

 side, keel rabbet to underside of upper deck. The 

 bulwarks were drawn at 28 inches height. Next, the 

 mast positions were decided by prorating from the 

 plan of the Ohio the position of each mast from the 

 fore perpendicular and then modifying these positions 

 slightly by use of masting rules contained in M'Kay's 

 book 20 of 1839. 



Since it appears that the Savannah may not have 

 been purchased for conversion to a steamer until near 

 the date of her launch and Ijecause of the lack of iden- 

 tification of the lithograph referred to by Collins, the 

 statement that the mainmast was placed farther aft 

 than normal was rejected. At launch her mast part- 

 ners would have been in place and the deck laid. Any 

 alterations in the position of the mainmast then would 

 have made it impractical for the owners to demand 

 them of the builders without heavy additional ex- 

 pense. In addition, the plan, as it was developed, 

 indicated no need for such alteration. 



The plan of the engine, drawn to the same scale as 

 the profile plan, was shifted about on the lower deck 

 in the hull profile to determine where the engine and 

 side paddle wheel shaft might be located. A little 

 experimentation and study made it certain that the 

 proper location could be estimated within a foot or 

 so, to scale, as to fore and aft positions. The after 

 end of the cylinder, and its piping, had to clear the 

 mainmast by at least 9 to 10 inches to allow removal 



" Letter from Carl C. Cutler to the author, November 24, 

 1958. 

 2" Op. cit. (footnote 5). 



of the cylinder head for inspection and repair. The 

 position of the wheels, stack, and masts in Marestier's 

 sketch of the ship make it certain that the engine was 

 on the lower deck, abaft the paddle wheel shaft. Due 

 to differences between the dimensions stated by Mares- 

 tier and in the Vail account books and what the 

 graphic scale in Marestier's engine drawings produce, 

 the exact dimensions of the engine are uncertain. 

 Nevertheless, they can be approximated with enough 

 accuracy for our purpose. As a result of this treat- 

 ment, it seems fully apparent that the engine was 

 abaft the paddle wheel shaft, with frame extending 

 abaft the mainmast on the lower deck; there does not 

 appear to be a practical alternative in the light of the 

 available evidence. This matter will be referred to 

 again. 



The size of the cylinder and its valve chest and the 

 inclined position of the cylinder indicate conclusively 

 that the valve chest was in the mainhatch, which 

 would normally be just forward of the mainmast. 

 Even then, the after flange of the cylinder would just 

 clear the lower deck, allowing 6 feet between decks, 

 as in the Ohio. The cylinder would have been about 

 6 feet long; the graphic scale indicated 6 feet 3 inches. 

 The diameter of the cylinder plus height of valve 

 chest seems to have been 5 feet 9 inches to 6 feet. 

 Because of the use of the crosshead and a connecting 

 rod, pivoted at crosshead, the oscillating rod (or 

 pitman) and piston together equalled twice the stroke 

 plus allowance for stuffing box, crosshead, and pit- 

 man bearings. Therefore, the engine's over-all 

 length, from head of cylinder to the centerline of the 

 side paddle wheel shaft, could not have been much 

 less than 15 feet 9 inches, and probably as much as 16 

 feet 2 inches, thus making the length at extreme 

 clearance of crank throw as much as 19 feet. These 

 dimensions indicate that the centerline of the side 

 paddle wheel shaft must have been from 38 to 39 feet 

 from the forward perpendicular. It is not clear how 

 the wheel shaft was mounted in the vessel. Taking 

 into consideration her depth and her reported draught, 

 light and loaded, the Marestier sketch, and the hull 

 structure then used, it seems reasonable to place the 

 centerline of the shaft (which seems to have been 

 about 7 to 8 inches square) about 12 inches above the 

 upper (or spar) deck to allow proper dip of the blades. 

 This position would have given proper blade im- 

 mersion at the mean draught of 13 feet. 



In order to get the engine below deck, and to get 

 the boiler or boilers placed, it was necessary to cut 

 a large opening in the two decks. It may be assumed 



72 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



