Purchasing a mobile crane is one of the most significant capital decisions a construction business, crane contractor, or plant hire company will make. With prices ranging from tens of thousands to well over a million pounds depending on type and capacity, getting the assessment process right is not optional — it is fundamental to protecting your investment and ensuring the safety of everyone who will work with the equipment.
At the centre of any rigorous pre-purchase process is the mobile crane evaluation form. This document — whether a standardised industry checklist or a bespoke assessment tool developed by an experienced inspector — provides a structured framework for assessing the condition, compliance, and operational readiness of a used crane before any money changes hands.
But an evaluation form is only as good as the person completing it and the scrutiny applied to the results. This guide explains what a comprehensive mobile crane evaluation form should contain, how to interpret its findings, and how to use the results to make a fully informed purchase decision.
What Is a Mobile Crane Evaluation Form?
A mobile crane evaluation form is a structured assessment document used to systematically inspect and record the condition of every major system, component, and compliance element of a crane. It provides a consistent, repeatable framework that ensures nothing important is overlooked during a pre-purchase inspection — regardless of the inspector’s individual approach or familiarity with a particular crane model.
Evaluation forms serve multiple purposes in the purchase process:
- They provide a comprehensive condition record of the crane at the point of inspection
- They create a documented baseline against which future condition assessments can be compared
- They support price negotiation by providing objective evidence of deficiencies and their estimated remediation cost
- They form part of the due diligence record that protects the buyer if disputes arise after purchase
- They may be required by insurers or lenders as evidence of the crane’s condition before cover or financing is arranged
A well-completed evaluation form is not just a technical checklist — it is a commercially and legally significant document that deserves serious attention.
Section 1: Administrative and Compliance Information
Before any physical inspection begins, a thorough evaluation form should capture the administrative and compliance documentation associated with the crane. This section establishes the legal and regulatory baseline for the purchase and should include:
Crane Identification • Make, model, and serial number • Year of manufacture • Fleet or registration number • Current ownership details and confirmation of clear title
Statutory Inspection Certificates In the UK, this means the current LOLER thorough examination certificate — confirming when the crane was last examined, by whom, and whether any defects were identified. The certificate should be in date and issued by a competent person or organisation.
For cranes sourced internationally, equivalent inspection documentation from the country of origin should be assessed, along with any re-certification requirements applicable in the UK.
Service and Maintenance Records The evaluation form should include a section for recording the completeness and quality of the crane’s maintenance history — logbooks, service intervals, records of major component replacements, and any previous incident or repair records.
Load Test Records Confirmation of when the crane was last load tested, to what standard, and by whom.
Operator and Safety Manuals Verification that the original operator’s manual, load charts, and safety documentation are present and legible. Missing or illegible load charts are a serious issue — they cannot always be easily replaced, and their absence compromises the safe operation of the crane.
Section 2: Structural Assessment
The structural integrity of a mobile crane is paramount. No amount of mechanical refinement compensates for a compromised boom or damaged chassis. A robust evaluation form will assess structural condition in granular detail.
Boom and Jib Sections • Visual inspection of all boom sections for cracks, dents, deformation, and corrosion • Assessment of pin and bushing wear at all pivot and connection points • Condition of boom extension mechanisms — telescopic sections should extend and retract smoothly and lock securely • Evidence of previous repairs or welding — any weld repair to a structural boom section should be viewed with significant caution and investigated thoroughly
Main Frame and Carbody • Inspection of the main structural frame for cracks, distortion, or collision damage • Assessment of mounting points and connection interfaces • Condition of counterweight mounting systems and any evidence of overload damage
Outriggers and Outrigger Beams • Extension and retraction under power — should be smooth and responsive • Locking mechanisms — pads and beams must lock securely in all positions • Structural condition — inspect beams for bending, cracking, or corrosion • Pad condition — outrigger pads should be intact and correctly specified for the crane’s outrigger loads
Slewing Ring and Slewing Mechanism The slewing ring is one of the most expensive components on a mobile crane and one of the most important structural assessments in the evaluation form. Check for: • Radial and axial play — excessive movement indicates bearing wear • Uneven or jerky rotation across the full slewing arc • Unusual sounds — grinding, clicking, or rumbling during rotation • Gear teeth condition on the slewing ring — inspect for wear, chipping, or cracking
Section 3: Mechanical Systems Assessment
Engine • Cold start performance — a genuine cold start provides the most accurate picture of engine condition • Oil condition and level — dark, contaminated oil may indicate extended service intervals or internal issues • Coolant condition — check for discolouration that may indicate contamination • Presence of oil, coolant, or fuel leaks around the engine block, turbo, and associated components • Exhaust smoke colour — blue smoke indicates burning oil; white smoke may suggest coolant ingress; black smoke points to fuelling issues • Engine hours recorded — cross-reference against service records to verify consistency
Transmission and Drive Systems • Smooth engagement and operation through all gear ranges • Absence of unusual noises, vibration, or slipping • Condition of prop shafts, differentials, and axle assemblies • Steering response — should be direct and free from excessive play
Braking Systems • Service brake performance — both static and dynamic • Parking brake effectiveness — the crane should hold securely on the maximum gradient it is likely to encounter • Condition of brake linings and discs where accessible
Section 4: Hydraulic System Assessment
The hydraulic system is the lifeblood of a mobile crane’s operational functions, and its condition has a major bearing on both performance and reliability. The evaluation form should assess:
Hydraulic Fluid • Condition and colour — clean hydraulic fluid should be translucent and amber-coloured; dark, cloudy, or contaminated fluid indicates degradation or contamination • Fluid level and evidence of consumption
Hoses, Fittings, and Connections • Visual inspection for leaks, weeping, cracking, or perishing • Condition of end fittings and swages • Age and general condition of the hose assembly — older hoses may be serviceable but approaching end of life
Hydraulic Cylinders • Condition of cylinder rods — inspect for scoring, pitting, or corrosion that can damage seals and cause leakage • Evidence of seal leakage around cylinder ends
Pump and Valve Performance • Operational testing of all hydraulic functions — boom extension, elevation, slewing, outrigger deployment, and any auxiliary circuits • Response should be smooth and progressive without hesitation, jerking, or unusual sounds • Check for pressure relief valve function and proper system pressure
Section 5: Electrical Systems and Safety Devices
Electrical faults on mobile cranes range from minor inconveniences to serious safety hazards. The evaluation form should cover:
Wiring and Control Systems • Condition of wiring harnesses — look for chafing, bare wires, or evidence of amateur repair • Condition and functionality of operator controls in the cab • Display screens and instrumentation — all gauges, warning lights, and digital displays should be functional
Safety Critical Systems This section of the evaluation form carries particular weight because these systems directly protect operators and site personnel:
- Load Moment Indicator (LMI) — must be functional, calibrated, and displaying accurate information
- Anti Two-Block (ATB) system — protects against the hook block being drawn into the sheave; must be tested and confirmed operational
- Rated Capacity Limiter (RCL) — verify correct function and calibration
- Slewing, travel, and elevation limit switches — confirm all limits function correctly
- Emergency stop systems — test all emergency stop circuits
Any non-functional safety device must be treated as a critical deficiency requiring immediate remediation before the crane enters service.
Section 6: Operator Cab and Ancillary Equipment
Cab Condition • Structural integrity of the cab • Condition of glass, seals, and weather protection • Functionality of heating and ventilation systems • Condition of operator seat and associated adjustment mechanisms • Visibility from the operator position to key working areas
Rigging and Lifting Accessories Where rigging equipment — hooks, sheave blocks, and wire rope — forms part of the purchase, each item should be assessed individually: • Wire rope condition — inspect for broken wires, kinking, corrosion, and correct spooling on the drum • Hook condition — check for cracks, deformation, and function of the safety latch • Sheave block condition — inspect for wear, bearing condition, and structural integrity
How to Interpret the Evaluation Form Results
Completing the evaluation form is only the beginning. Interpreting its findings accurately is where the real value lies.
Categorise Findings by Severity A useful approach is to categorise every deficiency identified on the form into one of three categories:
- Critical — deficiencies that prevent safe operation and must be remediated before the crane enters service. Examples include non-functional safety devices, structural cracks in the boom, or absent LOLER certification.
- Significant — deficiencies that do not immediately prevent operation but represent a material risk to reliability or compliance if not addressed promptly. Examples include hydraulic hose wear approaching end of life or slewing ring play at the upper limit of acceptable tolerance.
- Minor — cosmetic or low-priority items that can be addressed as part of routine maintenance. Examples include cab wear, minor corrosion on non-structural components, or worn operator seat upholstery.
Quantify the Remediation Cost For every critical and significant deficiency, obtain a realistic estimate of the cost to remedy the issue. This exercise converts the qualitative findings of the evaluation form into a financial figure that can be used directly in price negotiation.
Make a Go / No-Go Decision Some evaluation findings should be absolute deal-breakers — regardless of price. Structural cracks in the boom, evidence of an unreported tip-over, or a pattern of concealed deficiencies all indicate a crane that is either unsafe to operate or a seller who cannot be trusted. In these situations, walking away is always the right decision.
For cranes with remediable deficiencies and no fundamental integrity concerns, the evaluation form provides a clear basis for negotiating a fair purchase price.
Who Should Complete the Evaluation Form?
The value of an evaluation form is directly dependent on the competence and independence of the person completing it. For any significant crane purchase, the inspector should be:
- Independent of the seller — never rely on a seller-provided inspection as your sole basis for purchase
- Technically qualified in crane inspection and maintenance — ideally with specific experience on the make and model being assessed
- Affiliated with a recognised body such as the Crane Inspection and Certification Bureau (CICB) in the USA, or a LEEA member organisation in the UK
For high-value purchases, consider commissioning a manufacturer-trained technician or an independent structural engineer to supplement the standard evaluation form with a specialist structural assessment.
Final Thoughts
A mobile crane evaluation form is a powerful tool — but only when it is comprehensive in its scope, completed by a qualified and independent inspector, and interpreted with the rigour and objectivity that a major capital purchase demands.
Take the evaluation process seriously, invest in professional inspection support, and use the findings to drive an informed, evidence-based purchase decision. A thorough evaluation form is not a bureaucratic formality — it is the single most important document in protecting your investment, your workforce, and your business when buying a used mobile crane.
Leave a Reply