As stated in the previous chapter, the first water-tube boiler was built
by John Blakey and was patented by him in 1766. Several tubes
alternately inclined at opposite angles were arranged in the furnaces,
the adjacent tube ends being connected by small pipes. The first
successful user of water-tube boilers, however, was James Rumsey, an
American inventor, celebrated for his early experiments in steam
navigation, and it is he who may be truly classed as the originator of
the water-tube boiler. In 1788 he patented, in England, several forms of
boilers, some of which were of the water-tube type. One had a fire box
with flat top and sides, with horizontal tubes across the fire box
connecting the water spaces. Another had a cylindrical fire box
surrounded by an annular water space and a coiled tube was placed within
the box connecting at its two ends with the water space. This was the
first of the "coil boilers". Another form in the same patent was the
vertical tubular boiler, practically as made at the present time.
[Illustration: Blakey, 1766]
The first boiler made of a combination of small tubes, connected at one
end to a reservoir, was the invention of another American, John Stevens,
in 1804. This boiler was actually employed to generate steam for running
a steamboat on the Hudson River, but like all the "porcupine" boilers,
of which type it was the first, it did not have the elements of a
continued success.
[Illustration: John Stevens, 1804]
Another form of water tube was patented in 1805 by John Cox Stevens, a
son of John Stevens. This boiler consisted of twenty vertical tubes, 1¼
inches internal diameter and 40½ inches long, arranged in a circle, the
outside diameter of which was approximately 12 inches, connecting a
water chamber at the bottom with a steam chamber at the top. The steam
and water chambers were annular spaces of small cross section and
contained approximately 33 cubic inches. The illustration shows the cap
of the steam chamber secured by bolts. The steam outlet pipe "A" is a
pipe of one inch diameter, the water entering through a similar aperture
at the bottom. One of these boilers was for a long time at the Stevens
Institute of Technology at Hoboken, and is now in the Smithsonian
Institute at Washington.
[Illustration: John Cox Stevens, 1805]
About the same time, Jacob Woolf built a boiler of large horizontal
tubes, extending across the furnace and connected at the ends to a
longitudinal drum above. The first purely sectional water-tube boiler
was built by Julius Griffith, in 1821. In this boiler, a number of
horizontal water tubes were connected to vertical side pipes, the side
pipes were connected to horizontal gathering pipes, and these latter in
turn to a steam drum.
In 1822, Jacob Perkins constructed a flash boiler for carrying what was
then considered a high pressure. A number of cast-iron bars having 1½
inches annular holes through them and connected at their outer ends by a
series of bent pipes, outside of the furnace walls, were arranged in
three tiers over the fire. The water was fed slowly to the upper tier by
a force pump and steam in the superheated state was discharged to the
lower tiers into a chamber from which it was taken to the engine.
[Illustration: Joseph Eve, 1825]
The first sectional water-tube boiler, with a well-defined circulation,
was built by Joseph Eve, in 1825. The sections were composed of small
tubes with a slight double curve, but being practically vertical, fixed
in horizontal headers, which headers were in turn connected to a steam
space above and a water space below formed of larger pipes. The steam
and water spaces were connected by outside pipes to secure a circulation
of the water up through the sections and down through the external
pipes. In the same year, John M'Curdy of New York, built a "Duplex Steam
Generator" of "tubes of wrought or cast iron or other material" arranged
in several horizontal rows, connected together alternately at the front
and rear by return bends. In the tubes below the water line were placed
interior circular vessels closed at the ends in order to expose a thin
sheet of water to the action of the fire.
[Illustration: Gurney, 1826]
In 1826, Goldsworthy Gurney built a number of boilers, which he used on
his steam carriages. A number of small tubes were bent into the shape of
a "U" laid sidewise and the ends were connected with larger horizontal
pipes. These were connected by vertical pipes to permit of circulation
and also to a vertical cylinder which served as a steam and water
reservoir. In 1828, Paul Steenstrup made the first shell boiler with
vertical water tubes in the large flues, similar to the boiler known as
the "Martin" and suggesting the "Galloway".
The first water-tube boiler having fire tubes within water tubes was
built in 1830, by Summers & Ogle. Horizontal connections at the top and
bottom were connected by a series of vertical water tubes, through which
were fire tubes extending through the horizontal connections, the fire
tubes being held in place by nuts, which also served to make the joint.
[Illustration: Stephen Wilcox, 1856]
Stephen Wilcox, in 1856, was the first to use inclined water tubes
connecting water spaces at the front and rear with a steam space above.
The first to make such inclined tubes into a sectional form was Twibill,
in 1865. He used wrought-iron tubes connected at the front and rear with
standpipes through intermediate connections. These standpipes carried
the system to a horizontal cross drum at the top, the entrained water
being carried to the rear.
Clarke, Moore, McDowell, Alban and others worked on the problem of
constructing water-tube boilers, but because of difficulties of
construction involved, met with no practical success.
[Illustration: Twibill, 1865]
It may be asked why water-tube boilers did not come into more general
use at an early date, that is, why the number of water-tube boilers
built was so small in comparison to the number of shell boilers. The
reason for this is found in the difficulties involved in the design and
construction of water-tube boilers, which design and construction
required a high class of engineering and workmanship, while the plain
cylindrical boiler is comparatively easy to build. The greater skill
required to make a water-tube boiler successful is readily shown in the
great number of failures in the attempts to make them.
[Illustration: Partial View of 7000 Horse-power Installation of Babcock
& Wilcox Boilers at the Philadelphia, Pa., Plant of the Baldwin
Locomotive Works. This Company Operates in its Various Plants a Total of
9280 Horse Power of Babcock & Wilcox Boilers]