Substation GIS Hall SPMT Transload & Seismic Audit

Cable basement directly beneath SPMT travel path reinforced with heavy-duty structural steel propping towers (min 300 kN/post) to support combined SPMT + 120-ton bay gross weight.

Interlocking composite ground protection mats (minimum 50mm thickness) or structural steel plate runners laid across epoxy floor coating to prevent point loading cracking (≤ 3.5 MPa contact stress).

All removable chequer plate cable trench hatches and pipe basement covers bridged with certified steel jump spans resting on reinforced concrete trench perimeter curbs.

Substation outer roller shutter and inner airtight door operate under electrical interlock: outer door must be fully closed and positive air pressure (≥ 25 Pa) stabilized before inner door opens.

Transporter chassis, hydraulic power pack unit (PPU), and all rubber tires thoroughly degreased, washed, and dried. Sticky dust-arresting floor mats placed across vestibule threshold.

SPMT diesel PPU fitted with certified catalytic soot filter and spark arrestor, or fully converted to indoor battery electric / shore power cable supply to eliminate soot particulate contamination.

Continuous 3D laser tracker verifying clearance to energized adjacent busbars (≥ 3.5m safe distance) and overhead bridge crane hook envelope (≥ 500mm margin).

Foundation embedded anchor rails surveyed with optical theodolite. Precision PTFE sliding shoes greased with silicon dielectric compound for smooth final millimeter positioning.

Hydraulic gripper jacks locked onto slide rails to advance the bay at controlled creep speed (< 0.5 m/min) without inducing dynamic rocking forces on internal gas barrier insulators.

Epoxy-grouted foundation anchor studs torqued with calibrated hydraulic torque wrench to specified design values (≥ 450 N·m). Lock nuts and spherical washers engaged.

Seismic shear lugs fillet-welded to embedded foundation steel plates per IEEE 693 high performance qualification level (0.5g ZPA). Welds verified via visual and dye penetrant inspection (DPI).

Bay structural enclosure bonded to subterranean copper ground grid using dual high-conductivity flexible braided jumpers. Resistance verified ≤ 0.1 Ω.