The supply of all labour, equipment, and materials to construct a welding shop addition to the existing Track and Structure Building to accommodate electric arc welding operations; temporary shoring and dewatering as required for excavation; disposal of materials of construction including construction rubble, excavation materials, soils, materials, and equipment, as necessary; renovate the interior office, washroom, and lunchroom areas of the building to meet the needs of the employees and improve overall services. Construction of an outside welding gas storage with a gas manifold system feeding the interior of the new addition; an indoor lockable material storage area within the new addition; two (2) welding stations for TTC Rail Infrastructure Department supplied portable welding units and one (1) high frequency tools station; a central area within the new addition for rebuilding track switch frogs; provisions for heating, ventilation, and air conditioning (HVAC) systems including heating, cooling, exhaust, fresh air provisions, and natural gas distribution for comfort, air quality, and freeze protection, and filtration system for Weld Shop area; construction of a new prefabricated Flammable Materials Storage Building (FMSB), separate from the existing building; and provision and installation of a two (2) storey temporary trailer to accommodate TTC employees during construction renovation work in the Track and Structure Building.