In air

Capping a network of crowns, not one pole

Every crown on the register sits in one band, in air, so the part is rarely the hard call. The hard call is which poles the budget reaches this year and in what order.

The cap itself, specified

Two gaps to know about before costing anything

Both gaps change a budget line, so they come first. There is no per-size table for the pole range in any source behind this site: five sizes cover crown diameters from 140 mm to 460 mm (5.5 to 18 in), so an order is settled against measured crowns rather than looked up. And nothing described here vents. If a specification names a vented pole cap, or a termination enclosure carrying one, that is a different article from a different supply chain.

The programme question is not the product question. Capping one pole takes a paragraph; capping a network is a sequencing problem, because the part is cheap against the access that gets a crew to the crown. Fitted during an inspection already on the calendar, a cap costs its fitting minutes. Fitted on its own trip, it costs a vehicle, a crew and a traffic plan. That gap, not the unit rate, decides how far the line goes.

Mixed-age stock is the normal condition of a distribution or telecom register, and five sizes absorb most of one without a pole-by-pole take-off. The same cap goes onto wood, concrete, steel and composite crowns alike, so what moves a day rate is access, not substrate.

Which crowns go first when the budget covers a fraction

Four ways to rank a register, in the order they tend to survive a challenge from finance.

Poles carrying equipment

First, because the cap is not defending the pole. A crown over a transformer, a recloser or a telecom cabinet defends everything mounted below it, where replacement means an outage, a crane and connections remade. Against one avoided replacement the capping cost disappears.

Crowns that have already checked

Open checking is the one condition signal a survey collects without climbing, and it disqualifies nothing: the adhesive lining is claimed to run into the cracks and cavities as the cap recovers. Loss below the cap line removes a pole from the programme; checking above it does not.

Age read inside species

Age alone ranks badly, because two poles of the same year in different timber and different treatment are not in the same condition. Rank age within species, then within treatment class. The same ordering shows where capping would be spent on a replacement already due.

Coastal and hard-winter sections

These crowns are wetted and dried far more often than the register average, and water standing in an open check and then freezing is what widens it. Freeze-thaw protection is published for the push-on cap too, so an exposed section is worth capping even where a permit rules the torch out.

What the cap does at the crown, and what it never reaches

The first four are the manufacturer's published claims. The last three are geometry, and no cap changes geometry.

Sawn end grain is closed. The adhesive-lined cap is claimed to give 100% environmental sealing to IP68 over the cut top.
A crown that has opened is consolidated, because the adhesive is stated to penetrate the cracks and cavities rather than bridge across them.
Perching and nesting damage at the top is prevented, woodpeckers included.
Outages from flash-over and electrocution at the pole top are stated to be eliminated. That is the claim most likely to carry a capping line through a reliability review, so quote it as the manufacturer's, not as a measured network result.
It does not reach decay already established under it. A condition report putting the loss below the cap line is describing a replacement.
It does not reach the ground line, a different band on the same pole and a different part: pole protection sleeve.
It does not restore a crown that has lost its diameter. The cap is chosen against a measured one, so a top too soft to hold a diameter is outside the programme rather than at the front of it.

Four ways a crown gets closed on a live register

Which cap goes on is settled on pole caps. This is the choice above it: how the crown gets reached at all.

Route	What triggers the visit	What the register gets	Where it falls down
Cap on a visit already booked	An inspection, a conductor change or an equipment swap	Fitting minutes only, against work already happening	Coverage follows the maintenance calendar, not the risk ranking
A dedicated run down one feeder	The capping programme itself	A whole feeder closed in one pass, in ranked order	Carries the full vehicle, crew and traffic-management cost
Push-on caps where a flame is refused	A section that cannot take hot work while energised	The crown covered against birds, weather and freeze-thaw	No bond into the checks and no sealing claim of any kind
Defer to replacement	A condition report showing loss below the cap line	Nothing, correctly	Deferring a crown that still holds its diameter buys the replacement early

The permit sets the schedule more often than the part does

A gas torch at the crown of an energised distribution pole is a hot-work and clearance decision before it is a product decision, and on a live network that is usually what caps how many poles a crew reaches in a day. It is also why a programme written entirely around the adhesive-lined cap ends up buying push-on caps for part of its register. The argument is made on closing an end where a torch is not allowed and the procedure on fitting a cap with a gas torch; neither is repeated here.

What network owners ask before the first order

We specified a vented pole cap. Is this it?

No. Nothing on this site vents at a pole top. The one vented part in the manufacturer's end-cap range is a cable cap carrying a pressure relief valve, and it belongs on a cable end in a hot yard rather than on a crown: de-gassing end caps.

Do these go on telecom, street-lighting and floodlight poles?

Same job, smaller diameter, with one limit to check first: the published range starts at 140 mm (5.5 in), so a slim lighting column below that sits outside it. Measure at the top, not the base, because a tapered column is often a size or two smaller where the cap will sit.

The pole is already rotting. Is capping still worth the visit?

Only where the loss is above the cap line. Closing the top and consolidating a checked crown are both claims about the crown; neither touches decay established below it, or anything at the ground line. Where the report puts the loss under the cap, the money goes further up the feeder.

Does capping add 30 years to the pole?

No. More than 30 years is the quoted service life of the cap from a single application, which says how long the closure holds and nothing about the timber under it. Read it as the interval before the cap itself becomes a maintenance item.

How do we size an order across mixed stock?

Measure crown diameters across a sample of each pole class and bucket them into the five sizes covering 140 mm to 460 mm. No finer table is published, so there is no part number to look a diameter up in. Ordering variants sit on the manufacturer's own page for this cap, and the codes that do exist for the cable-side parts are on the size charts.

Where to read next

A crown diameter, a pole count and a permit answer

Those three lines are enough for a sized reply in one exchange. Add the substrate mix if the register holds more than timber, and say whether fitting rides on visits already booked or needs trips of its own, because that is the line that moves a programme cost rather than a part cost.

Contact Or specify the cap first