Open Top Containers for Heavy Machinery: Cut Time With Crane Loading

When your cargo won’t fit through a standard container door—or must be lifted in/out vertically—open top containers are the workhorse solution. The removable roof bows and tarpaulin allow crane loading/unloading of over-height, awkward, or heavy machinery, while still providing the stacking strength, weather protection, and global handling of a standard ISO box. Here’s how to plan open top moves end-to-end and avoid costly mistakes on the quay or at site.

What Is an Open Top Container (and When to Use One)

An open top container is a 20ft or 40ft ISO container with a removable roof (bows + tarp). You load from the top by crane (or high-reach), then lash and weather-seal under the tarpaulin. It’s the go-to for:

• Heavy machinery & plant (presses, CNCs, generators, pumps)

• Over-height assemblies that exceed door height but fit within width/length

• Top-lift only items (can’t be tilted or forked safely)

• Fragile equipment that needs a straight vertical lift into bespoke cradles

Not sure if it’s open top or flat-rack? If your cargo has side protection needs, fits within floor footprint, and benefits from a weather cover, open top usually wins. If it exceeds width or needs out-of-gauge (OOG) overhangs, flat-rack or breakbulk may be better.

Explore overall mode choices in Sea Freight vs Air Freight and international planning in our Ultimate Guide to International Shipping.

Typical Specs & Practical Limits (Quick Reference)

• 20′ Open Top: ~5.9m L × 2.35m W × 2.35m H (internal), payload ~28–30t (route/line dependent)

• 40′ Open Top: ~12.0m L × 2.35m W × 2.35m H (internal), payload ~26–28t (route/line dependent)

• Door header removal increases loading aperture height vs standard doors

• Roof bows/tarp remove for top lift; re-fit for weather protection and stacking

• Lashing rings on side rails/floor for chain/strap tie-downs (SWL per carrier spec)

(Exact capacities vary by carrier and container series; K&L confirms line-specific limits at booking.)

Why Crane Loading Saves Time (and Cost)

• True vertical lift reduces handling steps—no skates, no risky tilts

• Shorter site time when paired with pre-rigged lifting points and a ready crane

• Lower damage risk for high-value machinery (fewer contacts)

• Fewer site constraints—no need for wide door access or long forklift tines

To keep berth time tight during busy periods, see Mitigating the Impact of Port Congestion.

Planning an Open Top Move: Step-by-Step

1) Survey the Cargo

• Dimensions (L×W×H), center of gravity, lift points, and actual mass

• Removables (guards, skids) to reduce height and spread weight on the floor

• Shock/vibration and moisture sensitivity → need for cradles and desiccants

2) Engineer the Lift & Securement

• Lift plan (spreader, lifting beams, or slings with corner protectors)

• Cradle or skid with load-spreaders to protect the container floor

• Lashing plan (chains/straps/turnbuckles) to side/floor rings to the correct angles

Authoritative guidance on packing & securing: IMO/ILO/UNECE CTU Code (free, official).

3) Choose Equipment & Routing

• 20′ vs 40′ open top based on footprint, weight, and crane reach

• OOG height? Tarpaulin can “bulge,” but extra-height often incurs OOG surcharges—K&L validates with the carrier and terminal

• Route around low-capacity terminals; confirm special handling windows for top-lift units

4) Coordinate Crane & Site Readiness

• Book a suitable mobile crane (SWL, jib length, rigging) and certified operator

• Ensure ground bearing pressure is adequate; marshal area for safe radius

• UK lifting compliance: HSE—LOLER regulations

5) Pack, Lash, and Weather-Seal

• Fit corner/edge protection, block the base, and pre-tension lashings per plan

• Replace roof bows and tarp; seal per carrier instructions to keep stackable status

• Photograph all stages for insurance and handover records

6) Documentation & Compliance

• Commercial invoice & packing list with correct HS code and plain-English description

• OOG/handling approvals with the line (if applicable)

• Dangerous Goods declarations if machinery contains DG (e.g., batteries, oils)—see Hazmat Shipping

• Customs: align Incoterms, export licences, and any temporary import/repair reliefs (e.g., Inward Processing)

For broader regulatory context, see Trade Compliance.

Cost Drivers (What to Budget For)

• Equipment premium vs standard dry (open top hire + OOG if over-height)

• Crane/rigging time at origin and destination (including standby)

• Terminal handling (special lift windows, lifting bars)

• Lashing materials and certified cradles/skids

• Insurance valuation and potential survey fees

• Port congestion contingencies during peak seasons (read The Cost of Delays)

Open Top vs Flat-Rack vs Breakbulk: Quick Guide

K&L will model all three to balance cost, risk, and schedule.

Example: CNC Machine—40′ Open Top, Crane Both Ends

A 9.8m CNC (12.5t) ships on a custom steel skid with four lift lugs. K&L engineers a lift plan (spreader + soft slings), pre-positions a 60-tonne mobile crane at the factory, top-loads, blocks, and chains the base to side rails, replaces bows/tarp, and books a carrier window that accepts slight tarp bulge. At destination, K&L coordinates the receiving crane, lifts straight to plinth. Zero damage, one-hour quay dwell, no OOG surcharge.

How K&L Freight Delivers Open Top Projects

With 35+ years in project and containerised cargo, K&L Freight manages the entire operation:

• Cargo survey & lift engineering (drawings, WLL/SWL checks, CoG validation)

• Carrier & terminal approvals (open top allocation, OOG confirmation, special handling)

• Crane procurement and site method statements (LOLER-compliant)

• Packing, lashing & weather-sealing to CTU Code principles

• End-to-end execution with real-time milestones, photos, and PODs

Talk to us about Freight Forwarding or learn About K&L.

---

Key Takeaways

• Open top containers are ideal for heavy/over-height machinery needing crane loading and weather cover.

• Success depends on lift engineering, lashing, and carrier/terminal approvals—done early.

• Follow the CTU Code and LOLER for safe packing and lifting; document everything for insurance.

• K&L manages survey → crane → carrier → customs to keep dwell time and risk low.