Improvements in Compound Armour Plates.
Year: 1891

page_text: Date of Application, 12th Feb., 1891
Complete Specification Left, 11th Nov., 1891-Accepted, 12th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Compound Armour Plates.
I, TOLMIE JOHN TRESIDDER Captain, late of H.M. Royal Engineers now of
the Atlas Steel & Iron Works at Sheffield in the County of Yorkshire do hereby
declare the nature of this invention to be as follows:-
In the manufacture of compound armour plates the substitution of an ingot iron
6 containing nickel for the laminated wrought iron hitherto used for the backs of
the plates.
111 1.
.1
1001
T. J. TRESIDDER.
COMPLETE SPECIFICATION.
Improvements in Compound Armour Plates.
I, TOLMIE JOHN TRESIDDER, Captain, late of H.M. Royal Engineers now
of the Atlas Steel and Iron Works at Sheffield in the County of Yorkshire, do
hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
As usually made the backs of compound armour plates consist of numerous thin
plates of puddled wrought iron piled on each other and rolled together and re-piled
and re-rolled many times. The result is practically a mass consisting of alternate
laminæ of iron and slag. My invention substitutes for this mass a similar mass of
ingot iron (also called mild steel) into the composition of which nickel enters to
the extent of about 2 per cent.
The process of manufacture may be varied but I prefer to conduct it in the
following manner :-
I prepare a face plate of hard steel exactly as in the ordinary course of manufacture
of the "Ellis" compound plate but instead of uniting this face to a 'back of wrought
iron as usual I prepare an ingot of mild Siemens Martins steel to which an
addition of nickel has been made before tapping to the extent of about 2 per cent.,
and this ingot being pressed to the same dimensions as those of the wrought iron
back usually employed is substituted for it. The plate is then completed as an
ordinary Ellis compound plate. The nickel steel back is also equally applicable
to compound plates made in any other manner.
The object of this invention is to obtain increased resistance to punching
throughout the plate while reserving an intensely hard nature of face and avoiding
the liability to through cracking that would be possessed by a compound steel plate
in which the back was made of homogeneous mild steel not containing nickel.
The use of nickel as an ingredient in steel is of course no new thing and I have
been connected for some time with the manufacture of armour plates of homo-
geueous nickel steel. Compound armour plates wherein nickel should be used as
an ingredient of the face or middle have also occurred to me and I have made
such plates and had them tested by artillery fire.
Compound steel plates have also been made before and tested but without
satisfactory results on account of their liability to crack through their whole
thickness. Therefore I do not claim the use of nickel in steel nor the use of
nickel in steel armour nor the principie of compound steel armour but

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
In the manufacture of built up compound armour plates the use of homogeneous
nickel iron (also called nickel steel) in substitution for the laminated wrought iron
ordinarily employed in the backs thereof.
Dated this 2nd day of November 1891.
T. J. TRESIDDER.