1. Area of application and purpose

This technical regulation establishes a single procedure for conducting periodic inspection, non-destructive testing and maintenance of lifting mechanisms of bridge and gantry cranes on industrial enterprises in Ukraine. The procedure is developed based on the requirements of Norsok R-003, ISO 4309 (steel ropes), ISO 12488 (cranes — tolerances and manufacturing accuracy), DSTU EN 13001 (crane safety), as well as the Rules for Occupational Safety during the operation of lifting cranes, hoists and load handling devices (NPAOP 0.00-1.01-18).

This document is intended for reliability engineers, maintenance mechanics, and head mechanic service supervisors. The procedure should be carried out according to preventive maintenance (PMS), as well as after emergency stoppages or prolonged equipment downtime exceeding 30 days.

2. Safety Measures

WARNING OF HIGH VOLTAGE AND MECHANICAL ENERGY!
Before starting any work, perform a complete lockout/tagout (LOTO) procedure for energy sources in accordance with DSTU EN ISO 14118. Fully turn off the crane's main switch, lock it with a padlock, and post a warning tag: "DO NOT TURN ON! People are working."

PROHIBITED:

Being under a raised load or unsecured crane components without using certified safety systems.

Work at heights over 1.8 meters without a fall arrest system with a shock absorber and anchorage to reliable structural elements of the building or crane platform.

Adjusting brake mechanisms under load.
Required PPE (Personal Protective Equipment): safety helmet according to DSTU EN 397, safety goggles according to DSTU EN 166, protective footwear with a steel toe according to DSTU EN ISO 20345, high-strength work gloves, warning vest, fall arrest system for work at height according to DSTU EN 361 and EN 355.

3. Required Tools and Materials

Tool / Material Name	Technical specifications / description	Quantity
Torque wrench	Range 40–200 Nm and 100–500 Nm, error not more than ±4%	1 pc.
Digital Multimeter	True RMS, voltage measurement up to 1000V AC/DC, resistance and circuit continuity	1 piece
Laser rangefinder / ruler	Range up to 50 m, accuracy ±1.5 mm; metal tape measure 5 m	1 pc.
Vernier caliper	Range 0–150 mm, scale division 0.02 mm	1 pc.
Set of probes	Sheet thickness gauge 0.05–1.00 mm	1 unit
Ultrasonic flaw detector / MFD	Portable magnetic particle inspection (MPI) equipment or ultrasonic thickness gauge	1 pc.
Wire Rope Gauge	Special micrometer or vernier caliper for measuring wire diameter	1 pc.
Cleaner / degreaser	Industrial technical solvent (aerosol) for brake discs	3–5 cylinders
Wire Rope Lubricant	Special penetration wire rope grease with anti-corrosion additives	2–3 kg

4. Check list before technical maintenance

View Element	What to check	Acceptance / Rejection Criterion	Notes
Main circuit breaker	Lockout Tagout Status	Power supply is completely disconnected, lock is in place, sign is in position	Mandatory check with a multimeter at the terminals
Crane rails	Integrity of rails, joints, fastening	No cracks, joint displacement not more than 1 mm, bolts fully tightened	Check previous geometry laser scanning report
Metal structure of the bridge	Welds, corrosion, deformations	No cracks in stress concentration zones, deflection does not exceed the norm according to ISO 12488	Pay attention to the connections between the main beam and the end carriages
Cabin / Control Panel	Control organ reliability, emergency stop	The "Stop" button is held in the pressed position, breaking the safety circuit	Check the error light indication
ZIZ and equipment	Availability and condition of equipment	No damage to belts, carabiners, validity period has not expired	Check before each lift to the crane gallery

5. Step-by-step Maintenance Procedure

Step 1: General overview and preparation of the work area

Actual procedure: Perform the ascent to the bridge gallery using fixed stairs and a transition bridge with real handrails. Ensure there are no foreign objects on the span and galleries.
Energy Check: Using a digital multimeter (set to AC Voltage measurement mode, range up to 1000V) check for the absence of voltage on the main trolley or the flexible power cable of the cart. The voltage must be equal to 0.0 V.
Visual indication: Presence of zero potential at the main input of the control cabinet.
Typical error: Relying solely on switching off the circuit breaker at the bottom of the workshop without checking the voltage directly in the crane's incoming switchgear.

Step 2: Detailed inspection and measurement of the steel wire rope condition

Actual procedure: Clean the rope areas from old grease and dirt using a cloth and a special solvent over a length of no less than 1 meter in the most heavily loaded zones (wrap zones on the drum and blocks at the lower hook position).
Diameter measurement: Measure the actual diameter of the wire rope using a vernier caliper or micrometer in mutually perpendicular directions at three different sections. *Acceptance criterion:* A reduction in the diameter of the wire rope compared to the nominal diameter (value indicated in the crane's passport, usually 10-15% for constructions according to ISO 4309) is the basis for immediate rejection. If the nominal diameter of the wire rope is 20 mm, a reduction to 17.5 mm requires replacement.
Підрахунок обривів дротів: Підрахуйте кількість обірваних дротів на кроці свивки канату (довжина приблизно дорівнює 6-10 діаметрам канату). *Критерій прийняття:* Для стандартних багатопрядних канатів наявність більше 5 обірваних дротів на одному кроці свивки або більше 10 на двох кроках вимагає вибраковки канату згідно з ISO 4309.
Змащування: Нанесіть свіже канатне мастило рівномірним шаром по всій довжині робочої ділянки за допомогою пензля або спеціального аплікатора.
Typical error: Applying new lubricant over an old dirty layer without prior cleaning and inspection of hidden defects inside the rope strands.

Step 3: Inspection and Adjustment of Brake Systems

Actual procedure: Locate the main lifting brake (block or disc type with electric hydraulic pusher or electromagnetic drive). Inspect the condition of the friction linings. Measure the remaining thickness of the friction lining using a vernier caliper.
Допуски: Мінімальна допустима товщина фрикційної накладки становить 4.0 мм (якщо початкова була 10.0 мм). Зазор між гальмівною колодкою та барабаном/диском у розгальмованому стані має становити рівномірно 0.5 – 1.0 мм з кожного боку.
Gap adjustment: Release the locking nuts of the brake spring adjustment screws. Using a wrench, adjust the piston rod length and spring force. Check the travel of the electric hydraulic piston rod — it should ensure complete release without sticking.
Bolt Tightening: Tighten the brake mechanism mounting bolts with a torque wrench to 180–220 Nm (for M16 bolts with 8.8 strength class).
Typical error: Uneven adjustment of gaps on the left and right sides of the shoe brake, leading to binding, rapid wear of the lining and braking drum temperature above 70°C.

Step 4: Limit Switch Verification

Actual procedure: Check the functionality of the end-of-travel switches of the trolley, bridge and hoist mechanism. Inspect the levers, rollers and contacts for the absence of mechanical damage and play.
Electrical test: Connect the multimeter in resistance measurement mode (continuity test) to the normally closed (NC) contacts of the upper hook limit switch.
Mechanical activation: Manually (or carefully manually rotating the reducer shaft in the absence of power) activate the limit switch lever. The multimeter should detect an open circuit (resistance goes to infinity).
Control distance: Check that the actuation of the limit switch of the lifting mechanism occurs at a distance of no less than 200 mm from reaching the hook's highest projected point (the suspension block).
Typical error: Setting the limit switch too close to the upper position of the hook suspension, which causes impact of the blocks and rope breakage during inertial movement of the mechanism.

Step 5: Non-destructive testing (NDT) of the hook

Actual procedure: Clean the surface of the hook to a metallic shine in areas of maximum stress: the hook neck, the threaded part of the shank (when disassembled), as well as the hook bend.
Magnetic Particle Inspection (MPI): Apply magnetic suspension or use a portable electromagnet yoke. Check for the presence of surface and subsurface cracks. *Acceptance criterion:* Any indications of cracks on the hook are a definite reason for immediate rejection and removal of the crane from service.
Sound hook measurements: Measure the sound hook dimensions with a vernier caliper at the pre-marked control points (distance between the passport marks). *Acceptance criterion:* An increase in the vertical dimension of the sound hook exceeding 5% of the initial nominal passport dimension indicates deformation due to overload and requires immediate replacement of the hook.
Hook nut inspection: Inspect the hook nut locking plate. Ensure there is no self-loosening. Tighten the locking screws.
Typical error: Conducting a surface visual inspection of the hook without cleaning from dirt and paint, making the fatigue microcracks not noticeable.

6. Checklist after completion of technical maintenance

Testing / Test	Expected result	Status (Passed / Not Passed)
Lockout Tagout Removal	Circuit breaker is on, voltage on main busbars is normal	[ ] Passed [ ] Not passed
Final Switch Test (No Load)	Stop of the lifting mechanism 200 mm before the upper block	[ ] Passed [ ] Not passed
Brake function check	Stop without slip (skidding) during stop	[ ] Passed [ ] Not passed
Static Load Testing (+25%)	Lifting load by 100 mm, holding for 10 min, no residual deformations	[ ] Passed [ ] Not passed
Dynamic Load Testing (+10%)	Smooth movement and braking without shocks and external noises in gearboxes	[ ] Passed [ ] Not passed

7. Troubleshooting and Search Guide

Symptom	Likely cause	Removal actions
The lifting brake slips during lowering or lifting of the nominal load	Wear of friction linings, oil contamination on the disc/brake pad surface, spring weakening	Clean the linings with a technical degreaser, adjust the pre-tension of the brake springs, replace the linings when the thickness is less than 4 mm.
The end switch does not stop the mechanism in the extreme position	Failure of contact group of switch, jamming of lever, break in control circuit	Check the integrity of the contacts with a multimeter, clean the mechanism from dirt, replace the faulty limit switch.
Foreign metal noise (scratching, rattling) in the lifting reducer	Tooth wear of gears, oil deficiency or degradation, bearing damage	Perform oil analysis, refill the oil, check the clearance in the coupling, inspect the bearings using an endoscope, and carry out major reducer overhaul if necessary.
Vibration and shocks of steel wire rope on the drum	Incorrect winding of turns in the drum grooves, wear of the pressure roller, damage to the drum flange	Check the rope tension under load, re-arrange the rope on the drum without crossing the strands, check the condition of the drum grooves.

8. Recommended Technical Maintenance Schedule

Task	Frequency	Estimated duration	Personnel Qualification
Daily visual inspection (ropes, hook, brakes)	Every day before the shift starts	15 min	Crane operator / Fitter
Inspection and lubrication of ropes, brake inspection	Monthly	2 years	Fitter for Pump Repair (Level 3)
Full inspection of final switches, gaps and electrical equipment	Quarterly	4 years	Electromechanic / Mechanic
Non-destructive testing of the shaft (MPI/UT) and track geometry	Every year	8 hours	Engineering / Expert Organization

9. Spare Parts Catalogue

Description of the part	Typical Specification	Category UNITEC
Steel cable with organic core	See ISO 4309, diameter 16–28 mm, galvanized	Lifting mechanisms and ropes
Brake Pads and Linings	Safe Friction Material for YW/YP Series Brake	Braking systems of cranes
Final lever switches	IP65, 250VAC/10A, contacts 2NC+2NO	Electrical components and sensors
Load-bearing forged hooks with suspension	Strength class P or T according to DIN 15400 / DSTU EN 13155	Loading devices
Electric-hydraulic pushers brakes	Series Ed (Ed 30/5, Ed 50/6, Ed 80/6) 380V	Drives and stop devices

Are you looking for reliable European spare parts for bridge cranes and lifting equipment? Familiarize yourself with the complete range in our electronic catalog UNITEC-D.

10. References

ISO 4309: Hoist crane. Steel ropes. Inspection, installation, servicing and scrapping.
ISO 12488-1: Cranes. Construction tolerances and crane runway tracks. Part 1: General requirements.
DSSTU EN 13001: Crane Safety. Design Taking into Account Loads and Load Combinations.
NPАОP 0.00-1.01-18: Rules for the protection of workers during the operation of lifting cranes, hoists and load handling devices.
Norsok R-003: Safe use of lifting equipment.