842 REPORT—1899. 
Draught of water is, of course, practically determined by the depths available in 
the ports and docks frequented, or in the Suez Canal for vessels trading to the 
East. From the naval architect’s point of view, increase in draught is most desi- 
rable as favouring increase of carrying power and economy of propulsion. This 
fact has been strongly represented by shipowners and ship-designers, and not with- 
out result. The responsible authorities of many of the principal ports and of the 
Suez Canal have taken action towards giving greater depth. 
Other changes have become necessary on the part of dock and port authorities 
in consequence of the progress made in shipbuilding. Docks and dock-entrances 
have had to be increased in size, more powerful litting appliances provided, and 
large expenditure incurred, There is no escape from these changes if the trade of 
a port is to be maintained. The chief lesson to be learnt from past experience is 
that when works of this character are planned it is wise to provide a large margin 
beyond the requirements of existing ships. 
Cross-Channel Steamers. 
The conditions to be fulfilled in vessels designed to steam at high speed 
for limited periods differ essentially from those holding good in ocean-going 
steamers. None the less interest attaches, however, to cross-Channel steamers, and 
in no class has more notable progress been made. It is much to be desired that at 
this meeting some competent authority should have presented to the Association 
an epitome of the history of the steam packet service between Dover and the 
Continent. I cannot attempt it. So far as I am informed, the first steamer was 
placed on this route in 1821, was of 90 tons burden, 30-horse power nominal, and 
maintained a speed of 7 to 8 knots. She was built by Denny of Dumbarton, 
engined by David Napier, and named the Rod Roy. It is interesting to note that 
the lineal successors of the builder of this pioneer vessel have produced some of 
the most recent and swiftest additions to the cross-Channel service. 
In 1861-2 a notable advance was made by the building of vessels which were 
then remarkable for structure and speed, although small and slow when compared 
with vessels now running. Their designers realised that lightness of hull was of 
supreme importance, and with great trouble and expense obtained steel of suitable 
quality. The machinery was of special design and relatively light for the power 
developed. A small weight of coal and cargo had to be carried, and the draught 
of water was kept to about 7 feet. Under then existing conditions it was a 
veritable triumph to attain speeds of 15 to 16 knots in vessels only 190 feet long, 
less than 25 feet broad, and under 350 tons in displacement. To raise the trial 
speed to 20 or 21 knots in later vessels performing the same service, whose design 
includes the improvements of a quarter of a century, it has been found necessary 
to adopt lengths exceeding 320 feet and breadths of about 35 feet, with engines 
developing 4,500 to 6,000 indicated horse-power, and with very great increase in 
coal consumption and cost. On other cross-Channel services between Dover and 
the Continent still larger and more powerful paddle-steamers are employed. 
Another interesting contrast is to be found in the comparison of the steamers 
running between Holyhead and Kingstown in 1860 and at the present time. The 
Leinster of 1860 was 328 feet lung, 35 feet broad, and rather less than 18 feet draught. 
Her trial displacement was under 2,000 tons, and with 4,750 horse-power she made 
173 knots. She had a steam pressure of 25 lbs. per square inch; and was propelled 
by paddle wheels driven by slow-moving engines of long stroke. Her successor of 
1896 is about 30 feet greater length, 63 feet greater breadth, and about 10 per 
cent. greater displacement. The steam pressure is 170 lbs. per square inch. Forced 
draught is used in the stokeholds. Twin screws are adopted, driven by quick- 
running vertical engines of the triple expansion type. Very great economy of 
coal consumption is thus secured as compared with the earlier vessel, and much 
lighter propelling apparatus in proportion to the power, which is from 8,000- to9,000- 
horse power at the full speed of 23 knots. The hullis built of steel, and is propor- 
tionately lighter. 
This is a typical case, and illustrates the effect of improvements in shipbuilding 
