MINIMUM TREAD DEPTHOSHA 1910.25(f) 8.5”

ENTIRE FOOT IS STABLE

4” MINIMUM TREAD DEPTHOSHA 1910.25(e)

HALF OF FOOT IS UNSTABLE

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The study was conducted by the Department of Industrial Engineering at Virginia Polytechnic Institute and published in the proceedings of the Human Factors Society’s 32nd Annual Meeting. ©2019 Lapeyre Stair, Inc. All rights reserved. ATSvsShipStair012019

ALTERNATING TREAD STAIR SHIP’S LADDER/SHIP STAIRSVS

Virginia Tech conducted a study comparing alternating tread stairs to ship stairs and concluded that

alternating tread stairs have a clear comfort and safety advantage over ship stairs.

ALTERNATING TREAD STAIRS ARE SAFER AND MORE COMFORTABLETHAN SHIP STAIRS BECAUSE THEY HAVE MORE USEABLE TREAD DEPTH

TEST SUBJECTS STRONGLY PREFERRED ALTERNATING TREAD STAIRS OVER SHIP STAIRS FOR SAFETY AND COMFORT:

CHOSE FOR SAFER TREAD DEPTH89%

CHOSE FORSAFER ASCENT72%

CHOSE FOR MORE COMFORTABLE TREAD DEPTH85%

CHOSE FOR MORE COMFORTABLE ASCENT89%

CHOSE FORSAFER DESCENT82%CHOSE FOR MORE COMFORTABLE DESCENT85%

MORE RECORDED MISSTEPS BY TEST SUBJECTS WHEN USING SHIP STAIRS THAN ALTERNATING TREAD STAIRS

MORE OVERALL MISSTEPS73%MORE MISSTEPS WHEN DESCENDING WITH A LOAD129%

TEST SUBJECTS FELT LESS SAFE AND COMFORTABLE ON SHIP STAIRS THAN ALTERNATING TREAD STAIRS

FELT MORE LIKELY TO SLIP/TRIP ON ASCENT64%FELT MORE LIKELY TO SLIP/TRIP ON DESCENT85%