The spec is decided by washdown intensity, hoist duty class, and lift height, not just SWL: food-grade epoxy or 304/316 stainless contact parts, H1 grease, and IP65 minimum enclosure are the three non-negotiables on most lines.
For indoor process areas, a low-headroom (LX-type) or European-style under-running single girder on a 100-300 mm deep beam covers the bulk of 1-10 t duty cycles; for meat, dairy, beverage bottling, and CIP-room service, the under-running configuration is preferred because it eliminates the runway bottom flange from the washdown zone [S1][S4].
Selection criteria driven by washdown zone and duty class
Food and beverage plants are zoned by exposure: dry packaging, splash zones, and direct washdown. In dry packaging (snack bagging, dry-ingredient palletising), a standard top-running single girder with IP54 hoist is acceptable when the building envelope allows headroom. In splash and washdown zones (meat cutting, dairy processing, beverage bottling CIP), a low-headroom single girder crane with IP65 enclosure, 304/316 stainless load hook, food-grade epoxy paint (typical DFT 60-150 µm), and NSF H1 or H2 lubricant is required on all food-contact surfaces [S1][S4].
Hoist selection follows FEM/ISO duty class. For 1-5 t at 4-8 m lift, 6 m/min hoist speed, and 5-10 cycles/h, FEM 1Am (ISO M3) is the typical minimum. For 2-shift bottling or can-end palletising, FEM 2m (ISO M4) is the practical floor; bottling-line palletisers commonly run 15-20 cycles/h at 60-80% load factor, which pushes the hoist to M4-M5. Duty class and starts-per-hour together drive motor sizing and gearbox ratio; underspec'ing either shows up as brake wear and rope stretch within the first 12 months [S4].
Configuration: top-running vs under-running vs low-headroom
Three configurations dominate food-plant spec sheets. The under-running (suspension) single girder hangs the end trucks from the runway bottom flange, gives the lowest building cost, and keeps the runway out of overhead washdown spray; spans typically cap around 25 m. The low-headroom LX single girder sits the hoist between the girders, reducing hook-to-beam clearance by 300-500 mm versus a standard top-running unit, which is the cleanest retrofit into existing low-roof facilities. The European-style top-running single girder, with a wire-rope hoist mounted on a separate trolley and a fabricated box-section main girder, suits spans above 20 m and capacities above 10 t, where under-running end-truck wheel loading becomes the limit [S1][S4].
For span, capacity, and headroom, a single girder crane typically handles 1-20 t across 5-25 m spans; above 20 t, double girder construction becomes more common because a single beam section grows uneconomically. The choice between configurations is also a headroom equation: in a 6 m clear ceiling, a standard top-running unit may leave only 3-4 m of usable lift, while a low-headroom design recovers 300-500 mm. In a beverage warehouse with 8-10 m clear height, a top-running European-style unit is the standard pick [S1].
Materials, finishes, and contamination control
Stainless and food-safe finishes are the visible half of the spec. Load hooks, hook blocks, and any component within drip distance of the product zone should be 304 stainless as a minimum, with 316 specified where chloride exposure (CIP chemicals, salt-brines, cheese-curd lines) is expected. Carbon steel main girders and end trucks are typically painted with a two-coat food-grade epoxy at 60-150 µm DFT; the topcoat must be non-flaking, non-absorbent, and resistant to alkaline CIP detergents at pH 11-13 and acidic rinses at pH 2-4. Stainless or zinc-plated hardware, captive nuts, and sealed bearings prevent loose fasteners from entering the product stream [S1][S4].
Grease and lubricant specification is the invisible half. NSF H1 (incidental food contact) is the minimum on hoist gearboxes, hook bearings, and trolley wheels; H2 (no food contact) is acceptable on runway rails and non-product-zone components. White-oil or aluminium-complex H1 greases are standard. Bearing seals on hoist and trolley must be IP65 minimum, with IP66 specified in direct washdown; breather/drain plugs should be stainless to avoid rust staining on the girder soffit. For cold-room or freezer service (-25 °C to +4 °C), low-temperature H1 grease and cold-rated motor oil are mandatory, and brake coils need anti-condensation heaters [S1][S4].
Enclosure, electrical, and control standards
Ingress protection scales with washdown exposure. IP54 is acceptable in dry packaging aisles; IP55 is the practical minimum in splash zones; IP65 is the standard in direct-washdown and outdoor loading-bay service. For Class I Division 2 or ATEX Zone 2 solvent-handling areas near flavour rooms or ethanol-based extraction, the hoist and pendant must carry the matching certification; a non-rated pendant in a Zone 2 room is a common audit finding. Power supply is typically 380-480 V 3-phase 50/60 Hz, with 24 V control and a 110 V or 24 V pendant; VFD-controlled hoist and travel motions (1:10 speed range) reduce load swing and brake wear on 2-shift bottling duty [S1][S4].
Control architecture matters for cleanability. Pendant push-button stations should be sealed to IP65, with rubber-booted buttons and a strain-relief cable gland. Wireless radio-pendant control at 433 MHz or 2.4 GHz removes the pendant cable from the washdown zone and is increasingly common on premium lines, with paired push-button backup on the hoist. VFD line filters (per IEC 61800-3) limit conducted emissions back onto the plant bus, which matters when cranes share a feeder with VFD-driven conveyors. Crane manufacturers typically publish 6-12 m/min hoist speeds and 20 m/min travel speeds as the food-plant baseline; higher speeds shorten cycle time but require finer speed control to keep the load steady at low speed [S4].
Safety devices and compliance stack
The minimum safety stack on a food-grade single girder includes upper and lower hoist limits, overload limiter (typically set at 110% of SWL), travel limit switches on runway and bridge, phase-failure relay, and an emergency stop meeting IEC 60204-32 / ISO 13850. For 2-shift bottling and palletising, a slack-rope detector on the hoist drum and a 2-stage buffer on the end trucks prevent derailment at the runway joints, which is a recurring failure mode in fast-paced bottling halls [S1][S4].
Anti-collision and zoning become important when two or more cranes share a runway, or when a crane and an automated palletiser work the same aisle. Radio or infrared anti-collision modules maintain 2-3 m stand-off between adjacent bridges; a zoning interlock that cuts hoist travel outside a defined pick/drop envelope protects operators on the floor. Pendant and radio controls should be interlocked so only one station is active at a time, with key-switch handover between shifts. The full safety stack is generally governed by ISO 4301 (duty classification), FEM 1.001 / 9.341, and ISO 13849-1 performance level on safety functions; audit-ready documentation is part of the deliverable [S4].
Use cases and limitations
Single girder cranes are well suited to meat and poultry deboning lines (1-3 t at 5-7 m lift, splash zone), dairy and cheese processing (2-5 t, frequent CIP, pH 2-13 exposure), beverage bottling and canning (2-10 t palletising, 2-shift duty), and bakery and confectionery (1-3 t, dry to light washdown). They are not the right pick for sub-zero freezer service without cold-rated options, for 100% direct high-pressure hot washdown at >80 °C, for outdoor ship-to-shore bulk handling (use a gantry crane instead), for very heavy ladle or coil handling above 20 t, or for ATEX Zone 1 solvent extraction where a mobile crane or specialised ATEX hoist is the only compliant path [S1][S4].
Practical limits also show up in span and speed. Single girder construction is economical to roughly 25 m span and 20 t; beyond that, deflection control, end-truck wheel loading, and girder mass start to favour double girder designs. For ASRS-adjacent pallet handling in a 30 m span warehouse, a stacker crane on a dedicated aisle typically beats a bridge crane on cycle time and energy per move, and on crawler-mounted or rail-mounted heavy lifts, a crawler crane is the right tool. The right discipline is to spec the lightest configuration that handles 95% of the lifts and route the heavy or unusual lifts to a dedicated unit [S4].
Vendor landscape and buying discipline
Chinese OEM factories dominate the 1-20 t single girder segment, with European-style under-running, low-headroom, and standard top-running designs available ex-stock; the single girder crane range from factories like Xiecheng and the broader Henan/Shandong cluster typically offers FEM 1Am-2m duty, 1-20 t SWL, 5-25 m span, and 6-12 m/min hoist speed as configurable build options [S1][S4].
Buying discipline for a food-plant spec: lock the duty class and cycles/h first, then the washdown zone and finish package, then enclosure rating, then control and safety stack; capacity and span follow the process. Request a documented FEM/ISO duty calculation, a paint system datasheet with DFT values, NSF H1 lubricant certificates, and a third-party IP rating test report. For a complete selection framework, How to Choose a Single Girder Crane: 2026 Selection Spec Checklist walks the same checklist in question form. Where the building allows outdoor or aisle-mounted alternatives, Gantry Crane vs Overhead Bridge Crane: 2026 Spec & Selection Cut is a useful cross-check, and for the dock side of the same facility, Dock Leveler Selection Criteria 2026: Capacity, Lip, Drive and Duty Cycle pairs with crane spec at the loading point [S1][S4].