33 CFR §401.73

1. (a)Prohibitions. Cleaning and gas freeing of tanks shall not take place:
   1. (1)In a canal or a lock;
   2. (2)In an area that is not clear of other vessels or structures; and
   3. (3)Before gas freeing and tank cleaning has been reported to the nearest Seaway station.
2. (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. (1)The SLSMC Traffic Control Centre will accept the request to perform hot work under the following conditions:
      1. (i)Copy of vessel's “Hot Work Permit” is provided to the SLSMC before welding commences;
         1. (A)In the Welland Canal, send to: nerie@seaway.ca and nrshipinspectors@seaway.ca.
         2. (B)In the MLO Section, send to: cdo@seaway.ca and inspecteursvm@seaway.ca.
      2. (ii)Name of company performing the hot work is provided;
      3. (iii)Effective fire watch is maintained;
      4. (iv)Welding operations shall temporarily cease during vessel meets and lockages;
      5. (v)Welding operations shall cease at the direction of a Traffic Controller; and
      6. (vi)All sparks and/or flames are to be contained on the vessel.
   2. (2)[Reserved]
3. (c)Special requirements for tankers performing hot work. Prior to arriving at any SLSMC designated approach wall or wharf, a tanker must be gas free or have tanks inerted. The gas-free certificate must be sent to the SLSMC Traffic Control Center in order to obtain clearance for the vessel to commence hot work.