EMPLOYEE WAS ON A LADDER BESIDE THE TRACK AT SHED TAKING A CHECK SURVEY. THE MANTRIP HAD EXITED #1 SECTION AND TURNED THE CURVE. HE DID NOT SEE THE LADDER. MANTRIP SLID INTO LADDER, CAUSING LA DDER TO LEAN AGAINST BELT INJURING RIGHT KNEE. HE WAS TAKEN TO HOSPITAL WHERE X-RAYS WERE NEGATIVE.