Pricing steel ladders and the built-in ladders (steps) of inspection chambers: quantities by mass at design-shown dimensions, quota item attribution, and the "already inside the chamber item, not charged again" test

Topic Positioning

This card answers the two pricing questions of steel-access ladders: on what basis the quantities compute (theoretical mass / unit), and which quota item applies - and when they are "already inside the chamber item and need no separate charge". For steel ladders, access ladders and caged ladders, and the steps / ladders inside inspection chambers, across the building, structures, municipal network, urban rail and railway volumes.

Core Conclusions

1. Measurement: by mass at design-shown dimensions; holes uncut, connectors unadded

• General steel members (ladders included): DB11/T 2382-2024 clause 4.7.17 item 1: "steel members are computed by mass at design-shown dimensions, without deducting the mass of holes, welding rods, rivets and bolts unadded; rolled sections attached to hoppers or valleys merge into the hopper or valley quantities"; item 2: high-strength bolt assemblies, turnbuckles, shear studs, buckling-restrained braces (BRB), viscous dampers (VFD), tuned mass dampers (TMD) and seismic sliding bearings count by design-shown number.
• Municipal networks: clause 7.4.17: "steel platforms, steel ladders, steel guardrails, steel supports and steel bearings are computed by mass at design-shown dimensions".
• Chamber steps (when listed separately): SJG 111.2-2022 clause 3.2.4: "chamber covers and seats install by design-shown count per set; chamber steps install by design-shown weight in kg".
• Finished steps (structures volume): DB11/T 2382-2024 clause 9.3.5 item 6: "finished steps count by design-shown number".
• Unit note: quota units are mostly t while chamber steps are often reported in kg - unify before rate build-up (1 t = 1000 kg).

2. Item attribution: first decide "steel ladder" versus "chamber ladder / steps" - two wholly different routes

Route A: steel ladders (access ladders, caged ladders, roof steel stairs) -> steel-ladder items, by t

• Attribution: DB11/T 2382-2024 clause 4.7.10 - item 1 "steel ladders of ladder columns, strings, treads and platform plates execute as stepped steel ladders"; item 2 "embedded or welded-to-insert rolled-angle treads may execute as sundry steel members" (the port for embedded steel treads in chambers / tank walls); item 3 "column anchor bolts may execute as embedded parts".
• Beijing building volume: steel ladders take the stepped-steel-ladder items under other steel members, unit t.
• Beijing urban rail volume: item G1-4-171 "steel ladder", unit t, table G.1.22-4 ladder installation, work content "preparation, haulage, positioning, drilling, chemical-anchor installation, ladder installation, levelling, welding, rust and corrosion treatment etc.".
• Railway building works (TB/T 10831-2024 Volume 10, chapter 1 section 6 structural steelworks, V (5) steel ladder fabrication and installation): fabrication and installation separate, both by t - FY-737 to 739 fabrication (stepped / climbing / spiral), FY-740 to 742 installation; fabrication content "lofting, marking, cutting, straightening, drilling, assembly, welding, finished-product correction, numbering and stacking"; installation "setting out, unloading, inspection, marking, member assembly, stiffening, turning and seating, lashing and hoisting, correction, welding, fixing, touch-up painting".
• Railway communications (TB/T 10826-2024 Volume 5, section 4): TY-376 "fabricate and install tunnel-portal ladders" per "place" (cutting, welding, drilling, fixing, equipment marking, clearing) - not by t; follow the volume's basis.
• Municipal networks: steel ladders list separately by mass at design-shown dimensions (clause 7.4.17).

Route B: chamber ladders / steps -> mostly inside the standard-chamber items, not charged again

• Standard chambers price per "chamber" (or per m3 / count) with step installation inside the work content:
  • Municipal example D4-6-178 "concrete-block circular sewage chamber, 700 diameter, 400 pipe", unit "chamber", work content: "cover-slab installation, floor casting, walling, core-fill concrete, rebar, chamber step and cover installation etc." - a separate ladder / step item here double counts.
  • Railway subgrade (TB/T 10822-2024 Volume 1, chapter 6 section 3, V inspection chambers): LY-441 "chamber, reinforced concrete shaft" per 10 m3, content "formwork erection and removal, concrete casting, vibrating, curing, rebar fabrication and fixing, rung installation"; LY-442 "chamber, reinforced concrete cover" includes "formwork, cover precasting and installation, handle fabrication".
• Material conversion (changing no charge head): standard-chamber ladders are compiled in plastic-steel and covers and seats in heavy ductile iron - differing designs adjust the materials only, all else unchanged. SJG 181.4-2024 clause 3.1.3: "covers and seats in the standard-chamber items are compiled in heavy ductile iron, ladders in plastic-steel; where the design differs, adjust the cover, seat and ladder materials per the design, all else unchanged"; Hunan 2024 municipal standard (2025 edition in the source data), section note 5, the same, adding that plastic chambers assume non-paved carriageways and other chambers paved carriageways; standard chambers are compiled per 07MS101 (water) and 06MS201 (drainage) collections.
• Shaft adjustment: chamber shaft walling serves depth differences, counted by number banded by height, per 0.2 m up or down (Hunan note 7); depth means cover top to chamber foundation (or blinding top absent a foundation) (note 11).

Applicability Boundaries

• Measurement is always at design-shown dimensions, not as-built; under the theoretical-mass basis holes, rods, rivets and bolts are never adjusted.
• The first test of "list a ladder item or not" is the chamber item's WORK CONTENT: where it already includes "chamber step / rung installation" (D4-6-178, LY-441), no separate charge; only non-standard chambers, stand-alone installation or finished-product listing take separate items.
• Units differ by volume: railway tunnel-portal ladders per "place", standard chambers per "chamber", stand-alone steps in kg, general steel members in t - never one basis for all.
• Regional and sector quotas differ in item codes and work content; cross-region / cross-sector application must return to the executed volume's chapter notes and measurement rules - the codes cited serve their own editions.
• Material conversion changes materials only, never labour or plant, and is not a "change of charge head" - item attribution stands.

Further Reading

• DB11/T 2382-2024 Construction Works Consumption Quota Standard, clauses 4.7.10, 4.7.17 and 9.3.5; Annex G urban rail transit, table G.1.22-4 (G1-4-171); Annex D municipal works, table D4.36-2.2 (D4-6-178) - sections 4.7 structural steelworks, 7.4 networks, 9.3 masonry structures.
• SJG 111.2-2022 Consumption Quota Standard for Urban Utility Tunnels, Volume 2, clause 3.2.4.
• SJG 181.4-2024 Municipal Consumption Quota Standard, Volume 4 water supply and drainage networks, clause 3.1.3 (material conversion of standard chambers).
• TB/T 10831-2024 Railway Works Budget Quota Manual, Volume 10 building works, chapter 1 section 6 structural steelworks, V other steelwork, (5) FY-737 to 742.
• TB/T 10822-2024 Volume 1 subgrade, chapter 6 drainage, section 3 underground drainage, V inspection chambers, LY-441 to 442.
• TB/T 10826-2024 Volume 5 communications, section 4, tunnel-portal ladders TY-376.
• Hunan 2024 municipal consumption standard (2025 edition in the source data), inspection-chamber chapter notes (compilation basis, material conversion, depth and shaft rules).