40 



HARDWOOD RECORD 



Utilization of HardWoods 



ARTICLE XLII 

 WOODEN TANKS AND SILOS 



The woods used for the constructiou of 

 tanks, silos, vata and similar articles, accord- 

 ing to the Eagle Tank Company of Chicago, 

 include both hard and soft varieties, though 

 probably more of the former is used than 

 of the latter. 



Of the soft woods Washington fir and white 

 l)ine have always found greatest favor, the 

 consumption of fir showing a constant and 

 rapid increase, and that of pine falling off 

 year by year. This can be attributed to the 

 fact that clear pine is now very difficult to 

 secure, and, as the grade of "tank" demands 

 clearness of material, it is doomed to follow 

 the same path in this industry as it has in 

 others — gradually being substituted by other 

 species and ultimately being discarded en- 

 tirely. 



Of the so-called hardwoods Louisiana cy- 

 press easily holds the front rank, by virtue 

 of its familiar qualities of endurance and 

 resistance to water, as well as to the ease 

 with which it is worked, and to the fact 

 that stock of excellent grade and width is 

 readily obtainable. After cypress, plain white 

 oak probably is the next in importance, being 

 used, however, more for special work, and 



USUAL TANK CONSTRUCTION. 



usually cut two and one-half to three inches 

 thick. While poplar has found no inconsid- 

 erable use for the manufacture of tanks, it 

 does not now command an important position, 

 by reason of the prohibitive price of suitable 

 stuff, more than from any other cause. In 

 the manufacture of a certain line of goods, 

 such as bakers' dough-tanks, maple is quite 

 often employed, though for water tanks it is 

 not well suited. For the first-named purpose, 

 clear lumber two inches thick is generally 

 employed. In this connection it might be 

 apropos to state that two-inch lumber is, as 

 a general thing, used in tanks having staves 

 up to twelve and fourteen feet in length. 

 Larger tanks are of three-inch material. 



The ordinary tank is either open at the 

 top or fitted with a loose cover. For purposes 

 requiring air-tight or dirt-proof receptacles, 

 such as brewing, vinegar making, distilling, 

 rectifying and paper making, a permanent, 



tight top, similar to the bottom, is provided. 

 All tank lumber must be well seasoned, 

 requiring no re-drying, generally six inches 

 and up in width, and of standard lengths. 

 Upon receipt of shipment the lumber is all 

 dressed on four sides preparatory to manu- 

 facture, the various phases of which are gen- 

 erally taken care of by separate gangs. With 

 the exception of special orders all tanks are 

 made to standard dimensions, and staves and 



SILO SIDING, SHOWING TONGUE AND 



GROOVE AND ENDLESS JOINTING 



WITH SPLINE. 



heading stuff are cut in lengths which will 

 minimize waste to as great an extent as pos- 

 sible, an ordinary trimmer being used for the 

 purpose. 



The construction of top and bottom head- 

 ings might properly be considered the first 

 step in the general process. Planks of ap- 

 proximately the right length, and selected 

 for uniformity of manufacture, are laid to- 

 gether edge to edge. As there is no special 

 waterproofing or preserving preparation ap- 

 plied between joints, it is of paramount im- 

 portance that the adjacent edges fit abso- 

 lutely flat against each other; hence, a re- 

 dressing by hand is essential before marking 

 for cutting. When properly jointed the planks 

 nre marked at one operation, with a compass 



stick, and are then separately band-sawed to 

 the required circumference. Following this, 

 the edges are bored and fitted with maple 

 dowel-pins, and the pieces are reassambled for 

 finishing. Joints which show unevenness are 

 planed down by hand, and the edge is beveled 

 off all the way, around, this method of con- 

 struction providing a more rigid article than 

 I lie square edge. 



The first operation in stave construction is 

 cutting to the required length. From the 

 trimmer-saw, the pieces are placed on the 

 stave machine, a simple arrangement with a 

 carriage, designed to give the proper bevels 

 at one operation. The machine in use by the 

 Eagle Tank Company is especially constructed 

 for long jointing, and is so placed that at 

 the end of the operation the carriage will 

 have reached a position near enough to the 

 crozing machine to allow of the operator 

 taking the piece off and placing it directly 

 upon his table. The crozer employed by the 

 Eagle company is also a departure from the 

 ordinary type, it being so constructed as to 

 cut a bevel croze, which the company advo- 

 cates as being more etficient than the ordinary 

 square cut. As with the stave jointer, the 

 crozer is capable of adjustment for the va- 

 rious types and sizes of tanks, vats, etc., 

 liirned out. 



While manholes, lugs and similar patented 

 standard accessory parts are purchased out- 

 side, all hoops, both flat and round, are man- 

 ufactured and fitted in the shop, and shipped 

 with the tanks. This is an important branch 

 of construction, as the hoops are the only 

 means by which the assembled parts are held 

 in place, and inefficiency of material or con- 

 struction might result seriously. 



The manufacture of square or rectangular 

 tanks is a more simple operation, consisting 

 merely of proper sawing and fitting. Ee- 

 ceptacles of this type are completed in the 

 shop and shipped out entire. On the other 

 hand, silos are more difficult of construction 

 and require several features not embodied in 

 the regular tanks. Besides the fact that stock 

 of especially large dimensions is used, all 

 staves are similarly manufactured and are 



COimON RECTANGULAR TANK. 



