33 C.F.R. § 401.73
(a) Prohibitions. Cleaning and gas freeing of tanks shall not take place:
(b) Acceptance of hot work. Before any hot work, defined as any work that uses flame or that can produce a source of ignition, cutting or welding, is carried out by any vessel on any designated St. Lawrence Seaway Management Corporation (SLSMC) approach walls, Cote St. Catherine wharf or wharves in the Welland Canal, a written request must be sent to SLSMC, preferably 24 hours prior to the vessel's arrival on SLSMC approach walls or wharves. The hot work shall not commence until the hot work request is accepted and acknowledged by SLSMC Traffic Control Centre.
(1) The SLSMC Traffic Control Centre will accept the request to perform hot work under the following conditions:
(i) Copy of vessel's “Hot Work Permit” is provided to the SLSMC before welding commences;
[78 FR 16182, Mar. 14, 2013, as amended at 87 FR 12591, Mar. 7, 2022; 88 FR 14268, Mar. 8, 2023; 90 FR 1884, Jan. 10, 2025; 91 FR 12692, Mar. 17, 2026]