Installation guide for Armadillo manhole cover shell

Armadillo manhole cover shells are designed for temporary clamp-fitment over manhole covers in situations exposed to construction plant traffic.

It is a reusable or if necessary sacrificial accessory for Wrekin Tristar or Highway D400 manhole covers, installed either at the construction level or finished road level, before opening the road to normal service traffic.

Armadillo manhole cover shells also inhibit coarse debris from entering the gully, protecting the chamber and drainage system.

Armadillo manhole cover shells are designed to provide protection against vertical loading and trafficking from construction plant. They are not designed to resist horizontal or prising forces generated by surface planers, scrapers, or similar equipment.

Where surface scraping operations are anticipated, we recommend the following measures be adopted:

• Recess installation: Manhole covers and frames should be installed below the working surface level (e.g. set that the Armadillo shell is flush with the binder course level) to prevent scraping plant from catching the shell edges or fixings.
• Avoid proud installation: Armadillo units installed flush or proud of the running surface are at risk of mechanical damage or displacement if contacted by scraping equipment.
• Protection from plant interaction: Scraping equipment must not pass directly over or engage with the Armadillo shell, particularly at edges or lifting/keyway interfaces.
• Inspection after surfacing operations: Following any scraping activity, the Armadillo shell and its fixings must be visually inspected for; distortion or displacement, damage to keyway interfaces and loosening of fasteners.

Any damaged units must be removed and replaced prior to reopening to traffic.

Failure to follow this guidance may result in damage to both the Armadillo shell and the underlying manhole cover, including tearing of keyways.

Ensure the installed manhole cover’s surface and frame top edge are free of debris which might otherwise prevent intimate contact with the Armadillo. Also, ensure that the cover lifting keyways are clear of debris. 

Select the correct size Armadillo shell accessory and its pair of fasteners for the manhole cover requiring protection (i.e. to suit TriStar or Highway 600x600mm or 675x675mm manhole cover).

Correctly align the different shaped corners of the Armadillo with those of the manhole cover and gently place the Armadillo so its 4 protruding ‘tabs’ locate in the manhole cover’s prising slots.

Ensure the inverted ‘T’ nuts of the supplied fasteners are at the bottom of their respective bolt threads.

Insert one fastener through each of the two apertures on the Armadillo so that the inverted ‘T’ nuts locate in the underlaying manhole cover keyways.

Using a 14mm Allen key, tighten both fasteners to ensure that the Armadillo’s metal corners are in intimate contact with the manhole cover frame.

Note: Re-tighten the fasteners after a 24-hour period to cater for seal relaxation.

Leave the Armadillo shell in place until construction plant is no longer on site.

Removed Armadillo shells may be reused on the next phase of works, stored for future re-use or, if excessively damaged, sent for recycling (as a 100% recyclable ferrous material).