266 
MINUTES OE PROCEEDINGS OE 
THE LOCK OR TURN OE CARRIAGES 
AND THEIR 
TURNING- ANGLES. 
By Lieut.-Col. H. H. MAXWELL, E.H.A. 
9-pr. Bengal. 
Let R =radius of limber-wheel 30 in. 
a= distance of limber-book in rear of centre of axle 6*3 in. 
% 
/£=vertical height of point of contact of the limber-wheel with friction 
plate on trail, 28 in. 
b -half-width of trail at that point, 4*5 in. 
s = half-horizontal chord at point of contact of limber-wheel, 29’9 in. 
w—\ track or gauge of way less width of felloe, 29*6 in. 
A = turning angle, 44° 36' 28". 
B —breadth of space in which the carriage can just turn, 3O’82 ft. 
cl= horizontal distance between axles, 111 in. 
£'=half-width, 31*8 in., and 
1= length of pole pair of horses measuring from the centre of limber 
axle, 121 in. 
Then cos (A + <ft) = - cos cj>, 
w 
wherein tan <h = --- and s = \/h (2 r — h ), 
w 
and B = V + d cot X + a tan \ X + J\l 3 + (£' + -~r — a, tan \ A) 2 }. 
^ smA 
The figure shows the projections on a horizontal plane of the elements of 
the carriage which have an influence upon its lock and turning angle. The 
limber is shown in dotted lines with its axle parallel to that of the gun or 
wagon body, and in thick lines when the carriage is locked; that is, when its 
limber wheel is in contact with the friction plate on the trail. 
