Crate spec ticket
| Base | Skid sized to the unit's gross weight and footprint |
|---|---|
| Walls | Sheathed crate or open frame with a weatherproof cover |
| Hold-down | Lag bolts through mounting feet, braced against tipping |
| Moisture | Barrier bag, desiccant, VCI on bare metal |
| Lumber | HT-stamped for export; plywood exempt |
| Marks | Centre-of-gravity, lift points, no-sling zones, this-side-up |
| Quote needs | Inside dimensions, gross weight, destination, fill state |
What power and utility shippers crate
A utility or a power equipment maker ships a wide range of electrical hardware. Distribution and power transformers, medium-voltage switchgear lineups, protective relay panels, circuit breakers, capacitor banks, small generator sets, turbine and compressor spares, and metering equipment all go by crate in one form or another.
The common problem is weight sitting high. A switchgear cubicle is tall and narrow, with its mass near the top, and a transformer bushing is a fragile porcelain or polymer part sticking out of a steel tank. The crate has to prevent tipping and keep the load from contacting its bushings.
Transformers and generators have their own pages. Control panel crating covers the instrument side of the same projects.
Moisture is the quiet failure
Electrical insulation absorbs water. A transformer core or a switchgear bus exposed to damp air on a long transit can lose insulating quality before it is ever energized. That is why the packing includes a barrier bag around the unit, desiccant sized to the bag, and a humidity indicator that the receiver can check.
Shippers of oil-filled units tell us whether the unit ships filled or drained, and whether it carries a nitrogen blanket. These facts change how the load is handled and marked, and they are the shipper's to supply. We do not advise on fluid handling or hazardous materials classification; under 49 CFR the shipper owns those declarations.
Bare steel parts get VCI wrap. See our VCI and desiccant guides.
Securing tall and top-heavy units
Switchgear and relay panels need bracing at the top as well as the base. A strongback frame, diagonal braces and corner blocks stop the unit pivoting on its skid when a truck brakes. Lag bolts through the unit's own mounting holes connect it to the runners, and the crate walls carry no load from it.
For transformers, bushings and radiators are removed and crated separately when the manufacturer's instructions allow, then marked and packed in their own boxes with the same order number. The main tank is blocked at its jacking pads and lifting lugs.
Lifting points matter more here than on most loads. Wherever a sling must not touch, the crate says so in paint.
Specifications and buyer requirements
Utilities and engineering contractors publish their own receiving and packaging requirements, and the equipment manufacturer's shipping instructions add more. Our crate follows those documents. For general wood crate practice, ASTM D6039 and ASTM D6251 are the standards buyers cite most.
We hold no certification we can offer here. We build what your document describes, show you the member list and keep the spec.
Storm response changes the pattern. After a hurricane or ice event, a utility may need a large number of identical crates for replacement units in a short window, and a spec on file makes that practical.
Lanes and modes
Most utility freight moves by truck, often on a flatbed with a tarp, so the crate must be able to take weather as well as vibration. Overseas projects go by ocean, as a crate in a container or breakbulk on the deck for the largest units.
Texas and California both appear in the Bureau of Labor Statistics export profiles with machinery manufacturing among their export categories, and electrical equipment makers in those states ship from the Port of Houston or the Port of Los Angeles.
Export crates with solid wood need heat-treated, stamped lumber where the destination requires ISPM 15, while plywood panels are exempt.
How crating fits project and spares programs
A substation project ships in a sequence timed to the construction schedule. Foundations and cable go first, then the transformer, then switchgear and controls. Each crate must arrive when the site can receive it, so we plan builds against the shipping calendar you give us.
Spares for the same equipment sit in a warehouse. A relay panel crate designed for the project can be rebuilt for a spare, with the same markings and the same protection.
Give us a list of all items with their dimensions and weights, and say whether the receiving site has a crane.
Questions buyers ask
Can you crate a transformer with its bushings fitted?
Usually the manufacturer's shipping instructions decide that. Where bushings ship separately, we build a padded box for them marked with the same order number.
Does moisture really matter for switchgear?
Yes. Insulation and bus surfaces absorb moisture on long transits. A barrier bag with desiccant and a humidity indicator is the usual answer.
Do you handle oil-filled unit declarations?
No. Fluid, nitrogen and dangerous-goods declarations belong to the shipper. Tell us the state so we mark and pack the crate accordingly.
Can you build a lot of identical crates quickly after a storm?
If the spec is on file, a repeat run starts from it. Send the quantity and the date needed with the request.