Step irons — also called climbing irons or manhole steps — are steel bars cast or built into a concrete or masonry construction that together serve as a ladder. You find them in inspection chambers, manholes, cellars, shafts, quay walls and old chimneys: anywhere a loose ladder would be impractical or cannot be permanently present.
A step iron is usually a bent bar anchored into the wall at both ends, so the tread stands clear of the wall and leaves room for the front of the foot. The steps sit vertically above one another, typically at an even pitch in the order of 250 to 350 mm; consistency matters more than the exact figure, because the odd step out is precisely where people misjudge their footing.
Construction
- Material — formerly cast iron or bare steel, now usually hot-dip galvanised steel, stainless steel, or steel with a plastic encapsulation
- Slip resistance — the tread is ribbed or profiled with raised side stops so the foot cannot slide sideways
- Anchorage — cast into the concrete wall, or retrofitted into drilled holes with a resin anchor; the anchorage determines safety, not the bar itself
- Standard — for steps in underground man-entry chambers there is the European standard EN 13101
Where it applies
- Manholes and inspection chambers in the public realm
- Cellars, crawl spaces and pump chambers
- Service shafts and water tanks
- Quay walls, locks and jetties
Practical tips
- Check before you descend — corrosion at the point of embedment is the commonest cause of failure; if a step moves or you see rust staining around the fixing, do not use the ladder
- Combine with fall protection — at greater depths a guided type fall arrester (rail or cable) plus harness is required; step irons on their own are not fall protection
- Confined space — a chamber is nearly always a confined space: test the atmosphere, ventilate, never work alone and post a top man
- When replacing — remove condemned irons completely and make good the wall; a half broken-out step is more dangerous than no step at all
- Grab rail at the top — a telescopic or fixed handhold above the chamber rim makes getting in and out considerably safer
Related terms
- Climbing fall protection
- Fall protection
- Climbing formwork
- Concrete
- Manhole
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.