Popular Science Monthly 



863 



readily prepared and easily assembled straight 

 pieces of stock will replace 2,300 tons of steel 



bilge turn itself is formed of a laminated 

 section strongly connected to the previous 

 members. All the parts are adapted to be 

 entirely finished by machiner\^ 



Another particular construction differing 

 from the method previously followed is the 



^Tvw) fuel oil tanks 250 tons capacity 

 / with 7000 miles cruising radius 



use of what corresponds with the top 

 plate of the double-bottom in a steel 

 ship. This timber, of slightly less size 

 than the frame itself, is firmly bolted to 

 the centerline keelson at the middle and 

 then bent downward at each end on a 

 wedge-shaped block between it and the 

 frame member below the turn of the 

 bilge. The frame member is also bent 

 upward slightly so that both pieces of 

 timber are stressed under tension which 

 gives a much greater degree of rigidity. 

 Similarly the side member of the frame is 

 stressed by being bent in slightly at the 

 top and tied to the same frame on the 

 other side by means of the upper deck 

 beam, and a crosswise deck beam or 

 stiffener is used in the hold to add 

 rigidity to the whole frame. 



Careful Loading Is Necessary 



The use of the center longitudinal 

 bulkhead makes it necessary- to have 

 side instead of center hatches or openings 

 through which the cargo is deposited in 

 the hold. This means that no cargo can 

 be shifted from one side of the vessel to 

 the other after it is once in the hold. 

 While this necessitates careful loading of 

 the ship to give the proper trim, it offers 

 an additional advantage of providing a 

 cargo space clear of beam posts or pillars. 



The development of this unusual design 

 of wood ship has been under way for more 

 than three years, and it was a mere coinci- 

 dence that it was practically completed just 

 at the time of our declaration of war 

 against Germany. Mr. Donnelly is a me- 

 chanical engineer who learned his 

 trade as a pattern maker with a 

 famous printing press builder. He 

 became a consulting engineer on 

 wooden drydocks in 1898. It 

 was this experience which 

 evolved his plan of building 

 wooden ships. 



Two types of ships have been 

 devised, as shown in the dia- 

 grams. Two fuel oil tanks will 

 feed four high speed oil engines, 

 giving a cruising radius of seven 

 thousand miles, as shown above, 

 or a triple expansion steam 

 engine with a coal bunker capa- 

 city of five hundred tons will 

 give a cruising radius of five 

 thousand miles as shown at right 



Coal bunKers 500 tons capacity 

 'with 5,000 mile cruismg radius \ 



D 



"if- - -y--—/- \/- — ^4 



: A • X : X ! X Xj X : X:; 



Triple expansion 

 steam engine 



four water-tube 

 boilers 



