As the B&O built the main line west to Parrs Ridge, it had limited information about the operation of steam locomotives. Consequently, the company was uncertain if the engine's metal wheels would grip the metal rails sufficiently to pull a train up to the top of the ridge. The railroad decided to construct two inclined planes on each side of the ridge along which teams of horses, and perhaps steam-powered winches, would assist pulling the trains uphill. The planes, about a mile long on each side of the ridge, quickly proved an operational bottleneck. Before the decade of the 1830s ended, the B&O built a alternate route that became known as the Mount Airy Loop. The planes were quickly abandoned and forgotten, though some artifacts survive to the present.