Page:The Steam Turbine.djvu/67

 miles in all weathers and carried 90,000 tons of coal from Newcastle to Rotterdam.

The pinion on the table was removed from the vessel a month ago for the purpose of showing it at this lecture. As you can see it shows no sign of wear. The gearing is illustrated on page 52.

Gearing promises to play a very important part in war vessels for increasing the economy at reduced speeds. I explained the difficulty in obtaining good economy under such conditions, and by means of geared high speed turbines the efficiency will be greatly increased. The Turbinia Company are now constructing two 30-knot destroyers of 15,000 horse-power with this arrangement (page 54). The high pressure portion and cruising elements are geared in the ratios of 3 to 1 and 5 to 1 respectively to the main low pressure direct coupled turbine, and their use will increase the effective radius of action at cruising speed by nearly 50 per cent, over that of a similar destroyer without gearing.