Typical sections for routes and cross-ings.
Standard trench and duct details prevent site queries. Provide sections, banks, draw-pit spacing, and elevation/fall rules tied to drainage (245) and enclosure entry sealing (622). List clearances to other services (241–243) and show markers/covers for as-built accuracy (731). These details underpin reliable cabling for automatic HVM bollards (515, 347). Include one-sentence context that naturally links upward to the parent hubs (this section and the chapter hub). Add SIRA context with a link to SIRA Bollards (UAE) when relevant. Link installation pages only if helpful: What to Expect and Installation Guide.
Important: This is a general guide. For live projects we develop a tailored
Method Statement & Risk Assessment (MS/RA) and align with authority approvals (e.g., SIRA) where in scope.
934.1 Section library
Standard trench sections for power/control. Sections keep HVM bollard cabling dry and crash rated bollard controls reliable (246, 347).
Start with a baseline set of sections: single-duct runs, twin ducts, small duct banks, and multi-bank corridors. Show cover, bedding, and surround; specify long-sweep bends and minimum bend radii for control, power, and hydraulic hoses. Include gradients (fall to sump) so water drains away from enclosures & cabling (347) and from automatic lanes powered by cables & routing (515).
Provide variants for paved plazas, landscaped verges, and carriageway shoulders. For wet sites, add a perforated carrier drain below or alongside the duct, connecting to the bollard sump (616). Where utilities are dense, pair “shallow” detail options with shallow foundations (244) so the trench/footing strategy remains buildable.
| Aspect | What matters | Where to verify |
|---|---|---|
| Performance | Tested system (bollard + footing) | Global crash ratings |
| Operations | Duty cycles, fail-state, safety | Installation Guide |
934.2 Depth/cover rules
By voltage/signal type and crossings. Rules protect HVM bollard segregation and crash rated bollard EMC (515, 531).
Use differentiated cover bands for LV power to HPUs, SELV control, loop feeder, and comms. Maintain lateral separation or use barriers when sharing a trench. This reduces EMC coupling and supports clean signals for detectors and PLC I/O. Where depth is constrained (over structure, or above a utility), use protective sleeves and concrete capping, recorded in the as-built set (731).
Segregate accessory power and comms from motor feeds. At road crossings, increase cover or add steel conduit. Match the duct size to the duct fill ratio plus a spare for future pull-ins; avoid overfilling to control sidewall pressure. Cross-reference the routing plan with interface types (531) to keep signal integrity.
934.3 Draw-pit layouts
Spacing, benching, sump options. Good pits sustain HVM bollard maintenance and crash rated bollard uptime (615, 842).
Space draw-pits to suit pull lengths, bend counts, and cable type; smaller chambers at 30–50 m for control/comms, larger at 50–80 m for power. Show benching that sheds water toward the pit sump with freeboard above the outlet. Detail pulling quadrant protection and fixing points for sheaves to prevent cable sheath damage during installation.
Include lifting points and clear working offsets around lids so maintenance teams can remove covers safely, aligning with lifecycle & maintenance (842). Where bollard enclosures are nearby, provide short spur ducts with slack loops to simplify controller swaps (348).
934.4 Entries & glands
Elevation, sealing, drip loops. Entries stop water into HVM bollard enclosures and crash rated bollard pits (245, 334).
Terminate ducts so that entries sit above finished pit waterline and slope down from the enclosure. Add a drip loop before the gland plate. For multiple cables/hoses, specify multi-port transits with compression seals sized to the sheath OD. On hydraulic systems, use bulkhead fittings at the enclosure wall to decouple hose loads.
Tie entry details to drainage design (245) and to the foundation detail (334). On coastal or wash-down sites, add a breather drain and specify raised cable glands.
934.5 Identification & labels
Duct colors, route tags. Labels preserve HVM bollard as-built clarity and crash rated bollard tracing (731, 911).
Adopt a color or stripe convention for duct types (power/control/comms/hydraulic). Place durable route tags inside pits and at entry points; add surface markers or bricks where permitted. Record codes and pit references in the as-built model/drawings (731) and follow file naming rules (911) so route IDs remain traceable into O&M sets.
Ferrule and cable schedule conventions should match the controls documentation (I/O list template 523) and integration documentation (539). For safety notices, keep wording consistent with site safety signalling (353).
934.6 Crossing utilities
Protection sleeves, separation. Crossings prevent HVM bollard damage and crash rated bollard failures (241–243, 335).
When crossing existing services, survey first (241–242) and classify conflicts against depth classes (243). Use steel or HDPE sleeves with sealed ends; extend sleeves beyond the utility trench shoulders. Maintain vertical separation and add warning tape. Where no depth is available, reroute the array or adopt shallow mount foundations (244), coordinating with underground utilities (335).
At road crossings, specify extra cover, concrete encasement, and a larger sleeve for future capacity. Document each crossing with a clash ID and photo log, then capture the final alignment in the as-built set (731).
934.7 Expansion & settlement
Movement joints, slack. Details limit stress on HVM bollard cables and crash rated bollard terminations (347).
Introduce movement joints where duct routes pass through slabs, ramps, or transition from structure to soil. Provide cable slack coils near terminations and at pit entries to accommodate seasonal movement. Where settlement is expected, route ducts on a compacted bed with warning that reinstatement must preserve cover and gradient. Check enclosure terminations and employ strain relief bars or cleats inside the controller cabinet (528).
934.8 Test & prove
Pressure/water tests, mandrels. Tests verify HVM bollard pathways and crash rated bollard commissioning (615, 631).
Before pulling cables, mandrel every duct with the correct gauge and pull through a draw-rope. After backfill, run a leak test (timed water column) on sealed sleeves where specified. During pre-commission (631), verify continuity and insulation resistance (IR), then record results in the commissioning pack. Keep test photos and mandrel tags for the ITP (714) and SAT evidence (638).
934.9 Maintenance access
Covers, clearances, lifting points. Access sustains HVM bollard service and crash rated bollard repairs (365, 348).
Choose cover types for the surface (paving/roadway/landscape) that maintain slip resistance and load rating. Keep 300–600 mm of clear, level working space around lids; show lifting points and hinged or lightweight options where frequent access is expected. Route ducts so future pulls don’t require removing bollards, and coordinate with design for maintenance (365) and panel siting & access (348) to minimize downtime.
Related
External resources
- FEMA 426 / DHS: Building security context
- ASIS Risk Assessment Standard
- ASTM F2656 Overview (context for tested systems)
934 Ducting & Trench Details — FAQ
What cover depth should I allow for power vs control ducts?
Follow differentiated cover bands: deeper cover and/or protective sleeves for LV power to HPUs, and standard covers for SELV control/comms. Maintain lateral segregation or physical barriers to reduce EMC issues. Where depth is limited (bridges/overbuild), use concrete capping and record the deviation on the as-built drawings (731).
How far apart should draw-pits be placed?
As a rule of thumb, 30–50 m for control/comms and 50–80 m for power, adjusted for bend count, route geometry, and cable type. Increase frequency near complex crossings or when multiple ducts converge to keep pulls manageable and to protect sheaths during installation (615).
Which tests prove duct routes before cabling?
Run a mandrel pull to confirm bore and bends; then perform a timed water/leak test where sleeves or sealed entries are specified. After cable pulls, record continuity and IR readings for the commissioning pack, aligned to the ITP and SAT steps (631, 714, 638).
What’s best practice when crossing existing utilities?
Survey first (241–242) to locate and classify conflicts (243). Use oversized sleeves with sealed ends and maintain vertical separation. Where cover is insufficient, add concrete encasement or reroute using shallow-mount footings (244). Capture clash IDs, photos, and final positions in the as-built package (731).