REPOET OF CAPT. GEORGE B. M°CLELLAN. 33 



MILITAEY BEIDGES. 



The Birago trestle has been definitively adopted, but somewhat diminished in dimensions ; 

 his sectional ponton only partially, if at all. I saw none in use or in store. 



The boats are of wood, and are 20' X 5' X 2|' The balks are 18' X 5^" X 4" ; chesses, 

 12' X 10" X 1". The anchors are of two sizes, the smaller weighing 80 lbs. 



The wagons are drawn by six horses, and weigh, loaded, from 4,800 to 5,400 lbs. The balks 

 and chesses are secured on the wagons by bolts ; the boat is placed on top, bottom upwards ; the 

 cables, oars, anchors, &c., are placed under it. There are two oars and one boat hook for each 

 boat; buoys, sounding poles, &c., are provided. A bridge train consists of 32 boats, and 

 requires for its transportation 34 boat wagons, 5 store wagons, 1 travelling forge, 238 horses, 

 and a company of the train, (drivers,) consisting of 1 officer, 6 non-commissioned officers, and 

 119 drivers. The company of the train is organized only when the troops are placed on the 

 war footing, since horses are provided only in that event. 



Each division of pioneers has 1 bridge train, constituted as above. In addition each division 

 has also a light advanced guard trestle bridge train, which consists of 10 wagons, can follow all 

 the movements of artillery, and most of those of the cavalry. 



Some of the officers spoke very highly of the Birago trestle, but stated that it did not answer 

 well on a very boggy bottom. Nothing peculiar was observed in their manner of throwing and 

 dismantling the bridge ; it was well and rapidly done ; the formation of the various detachments 

 is similar to our own system. 



SAPS. 



Gabions — 30" high, exterior diameter 20", 7 stakes, bound by 4 withes at one end and by 3 

 at the other. 



Sap fagots are used, but are generally replaced by sand bags. Sand bags 10" X 15" empty, 

 6" X 9" when filled. Temporary crowning fascines are not used. 



The sap rollers are of 2 concentric gabions, in the English style ; the outer cylinder is 9' long, 

 3' 4" diameter at tha centres of the stakes, and has 23 stakes ; the inner cylinder is 7' long, and 

 1' 9" in diameter. The space between the two cylinders is stuffed with fascines, and the ends 

 closed by wooden circles of 2" stuff. The picks and shovels are quite light ; the latter have 

 straight handles. The usual handspikes, chocks, &c., are employed. 



The annexed sketch represents the sap hook. 



The opposit3 figure shows the butt of the reverse sap hook. 



Tlie annexed figure represents the butt of the berm sap hook, a chain being 

 fastcnc d to the ring and a hook to the end of the chain ; the hook is hooked 

 to Ihe wattling of the gabionade, and thus hold secure. 



