The herald., 1897-07-11

echoing and re-echoing in naval circles.
And here is the story in a nutshell:
When it was announced many months
ago that the United States was building
4 torpedo boat the speed requirements
OF which would enable her to run away
from anything afloat, England decided
to build a torpedo boat destroyer that
would be able to overhaul the American
boat. OF course John Bull did not an
nounce his decision from the housetops,
but nevertheless the secret leaked out.
1t 10 said here that the navy department,
hearing of this plan, tipped off the con-
tractor, and the result all the world
knows. But the navy department saws
wood and says nothing. The Porter has
20 far exceeded expectations as to at
once preclude the possibility Of falling
q prey to the Express, which is only
expected to come up to her speed re-
quirements, which fall below those al
ready demonstrated by the Porter.
Following is a description of the Ex
prese, something of which has already
been published in this newspaper. The
Express is now in process of construc-
ton at the shipyards of Laird Brothers,
at Birkenhead. Her engines will be
capable of attaining 10000 indicated
horse power. The power of this tiny
boat, for she is only $50 tons burden.
can best be appreciated by consider
ing the fact that she will be able to
develop fully as great an engine power
as the Renown, battleship now build
fox 1r-Iin 1x,i11 a;
placement Of 1880 tons. The, Express
will have as an armament one 12-pound-
er quick-firing gun, five and 3-pound-
er quick-fring guns, and two White
head torpedoes.
While 1t is not known with certainty
how the machinery will be arranged, or
the exact dimensions thereof, it is un-
derstood they will be as follows: Each
set Of engines will have four cylinders,
the diameters of which will be: High
pressure. 1S% inches; intermediate, 321a
inches; two low pressure of 331a inches.
Each engine is of the three-stage COM
pound type. the stroke for all cylin-
ders being Is inches. The most notice
able point about the engine lies in the
arrangement of the. valves. The high
and intermediate pressure cranks are
set opposite to each other, while the two
low pressure cranks are similarly To-
Gated, although at right angles to the
high and intermediate cranks
The arrangement described renders
the design of valves adopted possible.
All the valves are combined in pairs,
each pair having a common valve rod.
The result of this is a reduction of the
number of moving parts and renders
possible that very desirable arrange
ment Of placing the engine in less fore
and aft space. The air pump is worked
direct from the main crank shaft. This
latter Is prolonged through a small
crank shaft, coupling joining the t-1o
The diameter of the pump is 10 inches
and its length of stroke inches. The.
material used Is such as to render break
ages necessarily rare, for both piston
and top cylinder covers are made of
Forged steel.
A cylindrical copper condenser each
with 929h inch tubes is attached to ev-
cry main engine. The total cooling sur
face is 3040 square feet and the total
heating surface $500 square feet. The
crate surface is 178 square feet. In
front of the boilers are air bulkheads
the air inlet doors of which close an
tomatically whenever a bursting tube
or other accident causes an escape of
steam and resulting pressure on the
boiler side of the bulkhead.
The Porter, although not such large
boat, 10 much superior in many respects
The Porter Is classed as torpedo boat
neither her size nor her armament en-
utline her to figure as torpedo boat de-