518 



AMERICAN FORESTRY 



DliCK PLAN REPLACED BECAUSE OF DECAY. 



construction, as they reduce the number 

 of gunwale joints to a minimum. The 

 gunwale joints are always the first 

 points to cause trouble by leaking, and 

 so it is a big item to reduce these joints 

 to a minimum. Besides being cheaper 

 in cost, both before and after creo- 

 soting, the fir is lighter, resulting in a 

 draft of but 9 inches for a standard 

 barge 100 ft. x 20 ft. x 4 ft. 7 in. 



White oak has been used almost ex- 

 clusively in the past for the construc- 

 tion of model-shape steamboat hulls. 

 The present tendency is to use steel. 

 Cresoted timber is eliminated from 

 consideration for model-type hulls on 

 account of the necessity of framing and 

 cutting timbers during erection, which 

 would expose untreated surfaces if 

 creosoted timbers were used. It is 

 the opinion of the writer that the steel 

 hull will give more economical results, 

 for the reason that when the cost of re- 

 pairs on an untreated oak hull during 

 its life are added to the original cost, 

 the yearly charge will closely approxi- 

 mate that of a steel hull. 



These relations, however, do not ex- 

 ist in the case of "scow" pattern boats 

 and barges. A steel barge will cost 

 more than three times as much as an 

 untreated fir barge, and nearly three 

 times as much as a creosoted barge. 

 The lumber for these "scow" pattern 

 boats and barges can be advantageously 

 framed and bored before treatment. 



The first creosoted barges used in this 

 country were built in 1900 of pressure 

 treated yellow pine by the New Orleans 

 Office of the U. S. Engineer Corps. 



These barges are today in a perfect 

 state of preservation, and in all prob- 

 ability will be used for 10 to 12 years 

 longer. The cost of repairs has been 

 light, and the results so satisfactory that 

 no untreated barges are now built by 

 that office. 



The Rock Island District formerly 

 used the open-tank treatment. The 

 penetration was usually superficial, but 

 the cost is only 5 per cent of the total 

 cost of a fir barge. Last fall the writer 

 inspected a large number of these fir 

 barges built in 1908, and in no case was 

 any evidence of decay found on the 

 treated timbers, while in a number of 

 cases the untreated timbers had reached 

 an advanced stage of decay. It is, 

 therefore, evident that the small cost 

 of this treatment will pay good returns 

 on the money invested. In the case of 

 90 per cent heart Long Leaf Pine the 

 same conditions exist, as the penetra- 

 tion on the heart surfaces is usually 

 superficial. With the Short Leaf and 

 Loblolly Pine it has been our experi- 

 ence that this class of timber requires 

 so much oil to saturate the sap that it 

 often costs more than a 10-pound 

 pressure treatment. For treating barge 

 timbers the pressure treatment has, in 

 the opinion of the writer, a number of 

 advantages that make it a far more 

 economical treatment. First, from a 

 treating standpoint, it is possible to 

 treat either green or seasoned lumber. 

 Second, the exact quantity of oil in- 

 jected can be ascertained by the tem- 

 perature and gauge readings. Third, 

 the entire treatment can be regulated 



