Riveting.
Boilers to be riveted with 3⁄4-inch rivet throughout. All girth seams to be double riveted. All horizontal seams to be double riveted. Rivet holes to be punched or drilled so as to come fair in construction. No drift pins to be used in construction of the boilers.
Braces.
All braces to be of the crowfoot pattern, one and one eighth (11⁄8) inch diameter and the shortest to be no less than four feet (4) long and of sufficient number for thorough bracing, and to bear uniform tension.
Manholes, Hand Holes and Thimbles.
One manhole in top of each boiler with heavy cast iron frame riveted on middle of centre plate; one manhole near the bottom of each front head; head reinforced with a wrought iron ring two inches (2) square, riveted to heads with flush countersunk rivets two inches (2) pitch and to have all the necessary bolts, plates, guards and gaskets; two six-inch thimbles riveted to top of each boiler, each to have a planed face; one heavy 6-inch flange on bottom of each boiler, 12 inches from back end to centre of flange. There must be two braces, one on each side of manhole in front head; also to have three braces opposite manhole on back head below tubes.
Lugs.
Four (4) lugs riveted on each side of boilers, of good and sufficient size, with six one-inch rivets in each lug.
Castings.