New-York tribune., 1918-03-13

OF metal tc - ::alded ere placed be-
tween the electrodes. the current is
turned on and when the metal is at
the proper welding point pressure is
applied to joint the sheets. The per
cusslve system employs the copper
electrodes and calls for a sudden con-
tact of the plates which are to be
welded. The arc is technically known
as the autogenous system.
1t accomplishes the welding without
pressure, simply allowing the metals
to melt under the influence of the cleo
trlc current and then to mix and unite
as they cool. When cooled the sepa-
rate sheets of metal are so Joined that
they appear to the cursory eye to have
been always single piece.
Weakness of German system
The system devised by Mr.. Wilson
and tested out by Commander lesson
employs the arc principle. 1t was
evolved from welding plant import
ed from Germany. The imported svs-
tenn early developed one grave weak
ness; it used electric current at a
pressure of IS volts: the heat gener-
ated could not be controlled. and it
burned the steel at the jointures.
1t was also discovered through
long series of experiments that no Joint
could be as strong as it should be un
less a special welding alloy of carbon
and manganese were used. SLOWLY Mr.
Wilson eliminated all drawbacks. ex-
cept the binding light of the arc in
action. The men who will weld snips.
IKE those who join street railway rails
and cure fiat wheels on locomotives.
VIII have to wear helmets and blue
goggles.
But he did perfect device to con-
troll absolutely the amount of heat, SO
that the welding may be accomplished
without burning" The machines
which have been supplied to the Navy
Department and sto the government
shipyards for ship welding have al
ready been approved by Lloyd's reg
lister.
They consist of a generator set con-
sisting of high voltage motor, which
Will run on any commercial current,
coupled with a dynamo wired for 35
volts. This Supplies the welding cur
rent, which passes through a panel
equipped with solenoid, carbon and
control switch. To the panel are at
tached the cables of the welding iron.
This iron carries the welding alloy,
which in the process acts as one cleo
trode, while the ship plate or casting
forms the second electrode The heat
is constant. 1t is just sufficient to
fuse the welding material and the steel
to be welded.
The steel plates are beveled to form
a V-shape groove, into which the weld
ing alloy flows and hardens.
The weld leaves a welt at the top
of the V, but the reverse side ~of the
Joined sheets is left as smooth as
glass.
Saving in Engine Power
Here enters another argument in
favor of welding ships together. 1t
does away with overlapping plates. In
stead the surface of the hull in con-
tact with the water is smooth, which.
it is declared, so reduces friction that
at least 10 per cent of engine power
is saved.
During the repairing of the German
ships it was found that the heat con-
troll eliminated blowholes and the Stag
pits, factors that ordinarily weaken
JolntS.
Some of the welding machines are
being supplied now to shipyard
where moulds are being made in which
to cast entire ship sections of steel.
Myron F. Hill, of 35 Cedar Street,
who is an advocate of the cast steel
system of fabricating ships, declared
Yesterday that the building of a test
vessel, for which plans are now being
made. would mark the solution of the
war shipping Iroblom, as we'll as that
of providing mercantile fleet for the
United States when peace brings re-
newal OF trade competition on the
ocean.
The chief virtue urged for The sys.
tenn is that shipyards can be equipped
cheaply for turning out cast steel
sNips, and that the vessels can be built
seven times faster without increasing
the forces of labor at present en-
ploycd.