Mechanical's steel barricades protect its retreating defenders, though Bernard expects his forces to break through.
Steel plates sealed Mechanical's security entrance from floor to ceiling and wall to wall. A narrow opening beneath the turnstile admitted one person at a time, leaving those waiting exposed to gunfire from above.
Peter Billings reported that attackers had time to prepare on their side of the wall. As the defenders retreated, another set of plates was welded across the narrow staircase passage. Bernard Holland subsequently reported that he expected his forces to break through soon.
Steel plates seal the entrance wall to wall and floor to ceiling, with a narrow opening beneath the security turnstile; another barrier crosses the stairs.
The barricades are defensive obstacles in the fighting around Mechanical.