Skip to content
Quote 0
Order by 12pm for same-day despatch Part of the Thomas Dudley Group (opens in a new tab)

Technical Resources

Datasheets, installation guides and compliance certificates for the full TDUP range. Free to download, no sign-up.

Guides & Downloads

Free to download, no sign-up. Each file shows its type and size.

More guides and technical notes

Datasheets and certificates by category

Every product has its own datasheet. Search by product name or order code, or open a category.

Ancillary Products 4 documents

Hinged LPCB Security Plate

Hinged Safety/security Fall Protection Grid

Sealing Plate

Slide Out Mod Security Plate

Chambers 5 documents

D400 Durafix Chamber Section

D400 Durafix Max Chamber Section

D400 Durafix Plus Chamber Section

E600 Durafix Chamber Section

E600 Durafix Plus Chamber Section

Gratings 42 documents

480×350 Kerb Drain

B125 Gully Grate

C250 Gully Grate

D400 Gully Grate

E600 Gully Grate

F900 Gully Grate

Manhole Covers 84 documents

B125 Manhole Cover

C250 Manhole Cover

D400 Manhole Cover

E600 Manhole Cover

F900 Manhole Cover

Steel Recessed Covers 30 documents

10t Recessed Block Recessed Steel Block Infill

25t Recessed Block Recessed Steel Block Infill

40t Recessed Block Recessed Steel Block Infill

FACTA AAA Recessed Block Recessed Steel Block Infill

FACTA AAA Recessed Block Recessed Steel Shallow Infill

FACTA B Recessed Block Recessed Steel Block Infill

FACTA B Recessed Infill Recessed Muti-infill

FACTA D Recessed Block Recessed Steel Block Infill

Surface, Stop Tap & Boundary Boxes 36 documents

127×80 GRADE B 100B2S Surface Box

135×119 GRADE C Plastic Stop Tap Box

150×150 GRADE A 135an Gripfix Surface Box

150×150 GRADE A 135an Slotted Gripfix Surface Box

152×127 GRADE C Type A Surface Box

165×150 GRADE B 6150/135 Boundary Box

180×160 GRADE B 6150/150 Boundary Box

210×200 GRADE B 6153 Boundary Box

220×200 GRADE B 6150/180 Boundary Box

225×255 GRADE A 225an Gripfix Surface Box

300×300 GRADE A 300an Gripfix Surface Box

380x230x100 D400 6274 Gripfix Surface Box

380x230x125 D400 6270 Gripfix Surface Box

430×280 D400 Gripfix Surface Box

GRADE C 6110 Stop Tap Box

Standards & Load Classes

Access covers and gully grates installed in the UK should meet BS EN 124-2:2015, which divides products into six load classes by static test load — A15, B125, C250, D400, E600 and F900 — and guides which class to use in which environment, from pedestrian areas (A15) through to airport pavements (F900).

Every applicable Thomas Dudley product is also independently Kitemark tested, and our CD534 range is designed to fully meet — and in several respects exceed — National Highways’ CD534 (formerly HA104/09) requirements for trunk roads and motorways, including a skid resistance value of 78 PSRV against a 60 PSRV minimum, and a 150mm minimum frame depth.

Patented Lift-Out Hinge

Thomas Dudley’s patented lift-out hinge is a unique design feature fitted across our D400, E600 and F900 covers and gratings — a vertical drop-in design giving 135° hinging for superior site safety and genuine one-man operation across the majority of sizes.

Where full removal is needed — for man-entry access, for example — the cover can also be lifted out completely, adding an extra layer of safety on top of the standard hinged opening.

Cutaway drawing of the hinge with the cover closed
Closed
  1. 3mm clearance around the pin, so the hinges carry no load.
  2. Patented T-slot: the flattened hinge pin is too wide for the slot, so traffic can't knock the cover out.
  3. The hinges take no impact or wear, so they have an infinite working life.
  4. Three-point contact and close-coupled covers give a true non-rock fit.
Cutaway drawing of the hinge as the cover is lifted
Opening
  1. Built-in pry points for easy opening.
  2. The cover only lifts out at 90°, when the flattened pin fits through the T-slot.
  3. One person can lift the cover for inspection.

Load Testing

Every Thomas Dudley product is routinely load tested at our own in-house facility, capable of applying forces up to 999kN — enough to test every EN124 load class, plus an additional 10% for extra peace of mind.

We’re confident enough in our products that we offer an open invitation to visit and witness testing of any stock product you select, free testing of any competitor product you’d like to bring, and — because testing is destructive — a free replacement from our own stock for any Thomas Dudley product tested, delivered direct to your site.

A cover in our in-house load-testing rigA computer simulation of load spread across a cover and frame

Despatch & Delivery

Our 130,000 sq ft covered warehouse in Dudley is built around speed, reliability and complete visibility. Orders placed before 12pm are dispatched the same day, with next-day delivery available on request, and an industry-leading 5–7 working day turnaround on special options such as badging, locking and sealing.

Every order comes with full delivery tracking, progress updates through transit, and rapid Proof of Delivery documentation — plus full load pick-and-run services, free tail-lift offloading on request, and a FORS-accredited fleet.

A lorry being loaded with pallets of castingsOur warehouse, with castings stocked ready to despatch

Understanding Post-Installation Issues

Something not right after installation? These are the usual causes and the fix.

  • Rocking or Unstable Covers

    Likely causeUsually poor or uneven mortar bedding, a frame that's not level or has distorted during installation, or repeated heavy traffic loading over time.

    The fixUse high-strength bedding materials evenly applied, let installation materials fully cure before opening to traffic, use precision levelling tools, and follow Thomas Dudley's installation guidelines.

  • Premature Wear

    Likely causeExcessive clearance between cover and frame wearing the seating surfaces, or inferior materials in a non-Thomas-Dudley product.

    The fixThomas Dudley products are engineered with minimal cover-to-frame clearances, and our own foundry background and metallurgy expertise ensures every product meets the highest material quality standards.

  • Frame Settlement & Misalignment

    Likely causeSub-grade instability from poor soil compaction or unsuitable backfill, or an installation that skips steps or is rushed.

    The fixCarry out thorough site assessment and soil testing, use reinforced concrete surrounds with proper compaction, and follow Thomas Dudley's installation guidelines meticulously.

Need something specific?

If a document you need isn't listed yet, our technical team can send it directly.