The addition of weight to any vessel is a serious matter, as it usually results in a decrease of stability, a lowering of maximum speed, and an increased fuel consumption per knot. In general all of our naval vessels are more or less overweight. In peace this makes no great difference, for the stability is seldom affected and the increase in fuel used is slight. However, in the event of war we may pay an excessive price for the useless weight we have added in time of peace.
Weight and space are inseparably related. The addition of weight inevitably causes a decrease in the amount of available space. The effect of any given amount of extra weight increases with the decrease of the tonnage of the vessels considered, reaching a maximum with the submarine, a type of ship which by the very nature of its construction is in its final trim from the date of its commissioning. Further, in no class of vessel can the addition of weight be so easily detected or so accurately measured. A comparison between today’s diving trim and that of yesterday discloses the increase or decrease of weight directly.