STEAM-SHIPS FOR THE CHANNEL PASSAGE. 
9 
Dicey. A sketch* of this type of ship is given (in section) in 
Fig. 2. 
Imagine that an ordinary ship, 45 feet broad, and 350 feet 
long, is sawn right down the middle, longitudinally ; that the 
two halves are separated by an interval of 30 feet ; that a flat 
side is then fitted on the inner side of each half ship, and that 
they are then bridged together by a strong platform, which 
connects them rigidly. There is thus a clear waterway, or 
rectangular canal, 30 feet wide, along the whole length of the 
ship, right down the middle, open at both ends and at the 
bottom, but covered at the top by the lower deck of the saloons. 
Propulsion is effected by a pair of ordinary paddle-wheels 
placed in this canal, right amidships — one paddle being close 
to each flat side, with a clear waterway ten or twelve feet wide 
between them. 
I can quite bear out the promoters’ claim for this design in 
respect of easy and gentle motion in a rough sea. It is now 
more than tv/enty years since I first assisted at experiments 
with models of twin boats, and I have recently had the advan- 
tage of sailing in a schooner yacht of this build. I know that 
these ships are remarkably steady, and so far as concerns the 
mere question of immunity from sea-sickness, I think that they 
are only second to Mr. Bessemer’s plan. If sea-sickness were the 
only difficulty of the channel passage, I should desire nothing 
better than Captain Dicey’s ship to go across in. 
The objections are, that these vessels are unhandy, and steer 
badly, and that their form is ill adapted for speed. These are very 
serious faults, and render them unsafe vessels for the channel 
service. Our mail steamers frequently find it no easy matter 
to enter Calais harbour, or to cross Boulogne bar in safety, and 
they sometimes have to give up the attempt. Now every one 
who has experience of twin boats with flat sides, is aware that 
they cannot be depended on for steering in a heavy sea. Their 
flat sides make them answer the helm very sluggishly, and at 
the same time give double effect to the tendency of the waves 
to turn them against their helm. This is a bad quality in the 
open sea ; it might be a fatal quality in attempting to enter or 
leave a gutway in a cross sea — like Boulogne harbour in a 
south-wester. The danger is enhanced by defective propulsion. 
A twin ship has nearly twice as much wetted surface as an 
ordinary vessel of the same displacement. As a large part of 
* This sketch must not he considered authentic, except as regards its 
general shape, nor as being correct in its dimensions. The writer has not 
had access to accurate plans, but has only seen a model ; and as he was unable 
to speak favourably of the project, he did not think it right to apply to the 
promoters for information about details. The sketch is quite sufficient as 
an illustration to this paper. 
