IN SHALLOW AND DEEP WATER. 173 
In deep water the forms arrange themselves in somewhat the same order, the 
straight-sided ones having larger resistance than those with curved sides, and 
those with “easy” rakes less than those with the steeper rakes. 
Some additional experiments were made with the same shapes of ends and 
sides, but with smaller beam. The resistance per ton of displacement for all prac- 
tical purposes appeared to be constant, or, in other words, the resistance varied 
about as the beam within the limits of speed for vessels of this type. 
GROUPS. 
All the above forms were tried in groups of six, two abreast and three deep, 
and certain selected forms in groups of two, three, four, and five. In all cases the 
models were lashed close together, corresponding to the common practice in this 
country. 
The results for the groups of six are shown in Figs. 6, 8 and 9, Plates 87 and 88. 
It is interesting to note that some of the forms with straight sides show rela- 
tively better results when grouped together. This is probably due to the fact that 
they present perfectly flat sides and no spaces between, whereas those with curved 
sides offer places for the creation of extra wave-making resistance. 
On the whole, Nos. 2, 3, 4 and 8 are fairly good. No. 7 is, however, still a 
rather poor form. 
In groupings other than those mentioned above, some interesting facts develop, 
as may be seen from Fig. 10, Plate 89. The grouping is also shown on the diagram, 
and the curves are those for barges Nos. 2 and 8. 
In deep water the resistance per ton decreases slightly as the number of barges 
is increased. 
In shallow water, by adding one extra barge in front, either in the three or five 
combination, the resistance is actually decreased as compared with two or four 
barges. In other words, it is actually more economical to increase the load 50 per 
cent in the case where two barges are towed abreast. 
The explanation appears to be that the extra barge acts as a “bow” to the 
others and reduces the wave-making resistance, both by increasing length and re- 
ducing head resistance. 
In general it may be concluded that, although the ship-shaped form is perhaps 
the best, taking all things into consideration, a form such as No. 2, with a moderate 
take and curved sides, is practically as good, and when simplicity of construction 
and repair are taken into account, the latter form is to be recommended. 
DISCUSSION. 
THE CHAIRMAN :—Is there any discussion on the paper by Professor Sadler, entitled 
“The Resistance of Various Types of Barges in Shallow and Deep Water’? Are there 
