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Thompson Fabricating LLC
"Engineered Handrail Systems & Other Fabricated Products for the Water, Wastewater, & Architectural Markets"
Industrial Aluminum Handrail "TUFrail"
Architectural Railing
Access Hatches "TUFhatch"
-Exterior Hatch THG
-Interior Hatch TH
-Heavy Duty Hatch H20
-Watertight Series WT
Ladders "TUFladders"
Grating & Support Systems
Cover Plates
Stop Gates
CAD Drawings


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Exterior Access Hatches - THG Series

THG Guttered Aluminum Floor Hatch
Guttered Exterior Hatch


  • 1/4 aluminum tread plate
  • Aluminum hold open device with red vinyl grip
  • 316 stainless steel gas springs
  • 316 stainless steel hardware


Standard Size Charts
Model Single Leaf
Sizes and Weight
Width Length** Weight
THG-1A    2'-0" 2'-0" 60
THG-2A    2'-6" 2'-6" 81
THG-3A    3'-0" 2'-6" 88
THG-4A    3'-0" 3'-0" 100

Model Double Leaf
Sizes and Weight
Width Length** Weight
THG-1DA  4'0" 4'-0" 154
THG-2DA  4'-0" 6'-0" 208
THG-3DA 4'-0" 5'-0" 173
THG-4DA  5'-0" 5'-0" 215



  • Single leaf hatches are watertight for a 2 inch head of water
  • Odortight
  • Gastight
  • Watertight for a 4-10 inch head is available
  • Mebac slip resistant coating
  • Locking devices
  • Addition Sizes Available
    Upon Request

** Length measured on hinge Side

THG Hatches
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Single Leaf
download or view cad drawing
Double Leaf
download or view cad drawing

Exterior hatch


Specification for model "THG" Aluminum Access Hatch

Floor access doors shall be type "THG" (WATERTIGHT, ODORTIGHT and GASTIGHT) as manufactured by Thompson Fabricating, LLC (Birmingham, AL). Door leaf shall be 1/4" aluminum checkered plate reinforced with structural aluminum channels and shall be capable of withstanding a 300 pound/s.f. uniform load with minimal deflection. (Calculations will be provided to the engineer upon request.) The following items shall be type 316 stainless steel: slam locks, brackets, hinges and hardware. The door shall have a 316 stainless steel gas spring with integral hold open device which will assist in opening the door and shall lock automatically in the open position. The door shall open a minimum of 90 degrees. The aluminum gutter frame shall be provided with a 1 1/2" threaded drain fitting and shall have a thickness not less than 1/4" and shall incorporate a neoprene gasket that will reduce air leakage to less than 1 CFM per lineal foot of frame when the interior of the hatch is subjected to a 2 inch water column vacuum. All fasteners which penetrate into the "Dry" area of the hatch shall be sealed with "O" Ring Seals to prevent incidental water and gas leakage. The portion of the frame which is in contact with the concrete shall receive a protective bituminous coating.

Locking Devices
Slip Resistant Coating

NOTES: Independent Lab Test Reports are available upon request.
All double leaf access doors shall have two interconnected slam locks which latch at both ends of the plate and can be un-latched from a single point. "Watertight" for standard single leaf doors shall be for a 1" to 2" head of water.

Download Specifications Document Cad Drawing Single Leaf Cad Drawing Double Leaf


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