D.—4

16

APPENDIX lII—TEST OF PIECED SPRINGS AT AUCKLAND. 6th February, 1917. (See page 10.) The following test was carried out: The undercarriage of al5 ft. wagon, the. draw-bar of which had been fitted with a whole spring at one end and a pieced spring at the other, was placed against a W class locomotive with brakes hard on. The lengths of both springs were measured, and trammelled lengths observed. An F class locomotive was then butted violently against the end at which the pieced spring was placed. This operation was repeated twenty times—both pieced and whole springs being each time flattened. There was no apparent difference in behaviour of the springs, and on each beingmeasured the original lengths were found to be maintained ; and on the trammels being applied it was found that there was a small increase in length at the pieced-spring end owing to the cross-bearer at this end having slightly deflected. This was due to this end of the wagon being exposed to the heavier shock. The shocks were sufficiently violent to lift the wheels of this end from the rails.

APPENDIX IV.—DRAW-GEAR OF CLASS "A" BOGIE CARRIAGE.

APPENDIX V.—TESTS OF DRAW-BAR SPRINGS.