She was built throughout to meet the requirements of the Bureau Veritas Classification Society, with extra heavy scantlings, thus making her one of the strongest vessels of her class afloat.
The following are a few of her principal scantlings:
The center vertical keel is 48 inches deep by 17 1/2 pounds, fitted with a 36-inch by 17 1/2-pound rider plate on top of the floors with 4 1/2 by 3 inches continuous angles. The frames are 6 inches by 3 inches by 14 pounds, channels spaced 24 inches apart and continuous to upper deck, with web frames of 12 inches by 22 pounds channel, spaced every 24 feet. Solid floors are fitted on every frame, 20 pounds in the machinery space and 18 pounds elsewhere, and are secured to the vertical keel by 3 inches by 4 inches double angles. Deck beams are of channel section, 10 inches by 22 pounds on main deck, and 6 inches by 14 pounds on upper deck, all spaced 4 feet centers and secured to frames with substantial brackets. Three channel stringers are fitted in the lower hold, one on each side and between decks.
The shell plating is as follows:
Garboard 19 pounds to 16 pounds at ends; bilge and side plating, 17 pounds to 14 pounds at ends; shear strake, 60 inches by 20 pounds, and 17 pounds at ends; between deck plating, 10 pounds. The vessel is constructed with two complete steel decks, and is fitted with three gangways on each side for handling freight. The stern post is a steel casting, and the rudder frame and stem are forgings.
The passenger accommodations are very complete, and all conveniences for a large passenger business are provided. The main cabin on the upper deck is finished in mahogany, and has forty-two staterooms, with the dining room at the forward end. The galley and crew's quarters are directly under the dining room, on the main deck. Aft of the engine room on the main deck is a large smoking room, with connection to the main cabin by a grand stairway, all finished in mahogany, similar to the main cabin. Pilot house and officer's quarters are on the boat deck, on which are also located sixteen staterooms similar to those in the main cabin. The accommodations for second class passengers are under the main deck aft. The steamer has accommodations for 200 first and second class passengers, and is licensed to carry 2,000 excursionists.
The machinery consists of an inverted, direct-acting, triple expansion, surface condensing engine, with cylinders 21 inches, 34 inches and 58 inches in diameter, and 40-inch stroke, designed by the Craig Ship Building Co., and built in their own shops. The high pressure and intermediate cylinders are fitted with piston valves, and the low pressure cylinder with a double ported slide valve. All valves are worked by Stephenson double-bar link motion, and have adjustable cut-offs, actuated by screws in the arms of the reverse shaft. The reversing gear is direct connected with a steam cylinder 11 inches diameter by 16 inches stroke. All pistons are fitted with cast iron spring rings, the high pressure and intermediate bodies also being cast iron and the low pressure being cast steel. Piston rods are machinery steel, secured to piston by tapered ends and nuts, and to crossheads by cottars. Crossheads are cast steel recessed for crosshead pin boxes and fitted with composition slippers. Connecting rods are wrought iron, the upper end being forked with crosshead pins shrunk in. The crank pin boxes are cast steel lined with best anti-friction metal.
The framing of the engine consists of three cast iron housings of box section in front and back, the latter being fitted with guide surfaces provided with water back for circulation of cooling water. The bedplate is cast iron of box section, cast in one piece, with five main journals.
The lower main journal boxes are cast steel, lined with anti-friction metal, as are also the cast iron caps which form the upper part of the bearings. The crank shaft is of wrought iron, 12 inches in diameter with steel crank pins and cast steel webs. Line and propeller shafting is wrought iron, provided with forged couplings and supported by suitable spring bearings. The thrust bearing is of the horseshoe type, with adjustable shoes. The propeller is four-bladed, solid cast iron, 12 feet in diameter and 19 foot pitch.
Owing to the large amount of lime in the waters of Lake Michigan, a surface condenser was fitted to obviate any trouble with the scaling of boilers. The condenser is separate from the main engine, and is of the cylindrical type, with steel shell fitted with composition tube sheets and composition tubes tinned inside and out. The cooling surface is 2,500 square feet
All the pumps are independent of the main engine, and with the exception of the circulating pump, were furnished by Dean Bros. of Indianapolis, Ind. The air pump is of the simplex vertical type, 12 inches by 24 inches by 18 inches; and the main and auxiliary feed pumps are of the Admiralty duplex type, 8 inches by 5 inches by 12 inches. Two duplex pumps, 5 1/2 inches by 5 1/4 inches by 7 inches, and one simplex pump, 4 inches by 4 inches by 5 inches are also fitted for general water service and for pumping from the bilge. Water is circulated through the condenser tubes by a centrifugal pump, with a 10-inch suction and discharge, driven by a 6 inch by 6 inch vertical, direct-connected engine, supplied by the Morris Machine Works of Baldwinsville, N.Y.
Steam is generated by four water tube boilers with an aggregate heating surface of 7,500 square feet. These boilers were tested to 450 pounds hydrostatic pressure, and are allowed a working pressure of 225 pounds.
The PURITAN is lighted throughout with electricity, generated by two 15 kilowatt direct-connected General Electric Co. generators, located in the engine room. She is also fitted with steam steering engine and a Hyde steam windlass. Her anchors are of the Baldt stockless type, and weigh 2,840 pounds each.
Taken altogether the PURITAN exemplifies the highest class of vessel for the trade in which she is employed, and is a credit to both her owners and builders.
Although she has only been running altogether about six weeks she has already broken the record for the run between St. Joseph, Mich., and Chicago, beating the best time of the whaleback steamer, CHRISTOPHER COLUMBUS, thus ranking her as one of the fastest boats on Lake Michigan. Her time for the run was 3 hours and 11 minutes, making an average of 19 3/4 miles per hour. She now averages 108 revolutions with 200 pounds of steam.