Setup, Assembly, and Disassembly of Cranes

Installation, Assembly, and Disassembly of Cranes

Chapter Introduction

The installation, assembly, and disassembly of a mobile crane constitute the most critical phase of the work cycle. More than 60% of fatal mobile crane incidents occur during these operations, according to data from the Canadian Standards Association. This chapter covers the fundamental principles, safe procedures, stability calculations, and regulatory requirements that every Red Seal exam candidate must master.

1. Fundamental Principles of Stability

1.1 Centre of Gravity and Stability

Crane stability is based on the balance between the overturning moment (load + boom) and the stabilizing moment (crane weight + counterweights). The combined centre of gravity (crane + load) must always remain within the support polygon.

The support polygon is the area bounded by the crane's points of support. For a crawler crane, this is the rectangle formed by the tracks. For a truck crane with outriggers deployed, it is the rectangle formed by the four outriggers.

Fundamental overturning moment formula:

Overturning moment (OM) = Load weight (L) × Horizontal distance (D)

Stabilizing moment (SM) = Crane weight (W) × Distance from centre of gravity to tipping point (d)

The stability condition requires that: SM ≥ 1.5 × OM (minimum safety factor of 1.5 for mobile cranes per CSA Z150).

1.2 Factors Affecting Stability

Factor	Effect on Stability	Consideration
Wind	Increases overturning moment	Reduce load according to load chart
Uncompacted soil	Outrigger settlement	Use cribbing/crane mats
Slope	Shifts centre of gravity	Level crane to ±1%
Centrifugal force	Increases dynamic load	Reduce swing speed
Dynamic load (hoisting)	10–25% load increase	Impact factor per CSA Z150
Temperature	Affects hydraulic viscosity	Cylinder stabilization time

1.3 Ground Bearing Pressure Calculation

The pressure exerted by outriggers on the ground must be calculated to prevent settlement:

Pressure (kPa) = Outrigger load (kN) ÷ Pad area (m²)

Example: A crane exerts 180 kN on one outrigger. The pad measures 0.6 m × 0.6 m.

Area = 0.6 × 0.6 = 0.36 m²

Pressure = 180 ÷ 0.36 = 500 kPa

If the soil bearing capacity is 300 kPa, a larger pad is required:

Required area = 180 ÷ 300 = 0.6 m²

Minimum dimensions = √0.6 = 0.775 m × 0.775 m

Rule of thumb: Typical soil bearing capacities are 100–200 kPa for clay soil, 300–500 kPa for compacted gravel soil, and 1000+ kPa for concrete.

2. Site Preparation for Installation

2.1 Ground and Work Area Assessment

Before any installation, the operator must perform a site assessment in accordance with CSA Z150-16, Article 4.3. This assessment includes:

27.Visual inspection of the ground to detect soft spots, recent backfill, and cavities

28.Verification of underground utilities (gas lines, electrical cables, water mains) — contact local authorities

29.Slope evaluation — the crane must be leveled to within 1% (1 cm per metre)

30.Identification of overhead obstacles — power lines, structures, trees

31.Verification of maneuvering space — the boom swing area must be clear

Minimum clearance from power lines (Canadian Electrical Code, Part I, Chapter V, Rule 8-200):

Line Voltage	Minimum Distance
0 to 750 V	3 m
750 V to 75 kV	4.5 m
75 kV to 250 kV	6 m
250 kV and above	6 m + 10 mm per kV above 250 kV

2.2 Cribbing and Crane Mats

Cribbing (outrigger pads) must be used systematically under outriggers when the ground is not reinforced concrete. Requirements:

Minimum area: calculated based on ground bearing pressure (see Section 1.3)

Minimum thickness: 50 mm of steel or 200 mm of treated hardwood

Positioning: centred under the jack, flat, with no gaps

Surface area: pads must be large enough to fully support the outrigger float

Crane mats: For very soft ground, use timber mats (typically 1.2 m × 1.2 m × 100 mm) stacked in a crisscross pattern to distribute the load over a larger area.

2.3 Crane Leveling

Leveling is performed using the outrigger jacks and a spirit level or digital inclinometer. The maximum tolerance is 1% (1 cm/m) in all directions.

Leveling procedure:

44.Deploy outriggers to their maximum extension

45.Extend the jacks until the wheels no longer touch the ground (25–50 mm clearance)

46.Check longitudinal and transverse level

47.Adjust jacks individually

48.Re-check after counterweights are installed

3. Boom Assembly

3.1 Boom Types and Their Characteristics

Boom Type	Advantages	Disadvantages	Typical Applications
Telescopic boom	Quick setup, no loose parts	Limited reach	Urban job sites, general lifting
Lattice boom	Long reach, lightweight	Long assembly time, multiple parts	Large job sites, wind turbines
Lattice boom with fly jib	Maximum reach	Reduced stability, complex assembly	High-rise work
Offset jib	Extended reach	Capacity reduction	Window installation, HVAC

3.2 Lattice Boom Assembly Procedure

Lattice boom assembly follows a precise sequence:

54.Position the crane on a level surface, outriggers deployed

55.Install counterweights according to the assembly chart (typically 50–100% of total counterweight)

56.Assemble boom sections on the ground, on horses

57.Align pins — pins must be inserted without excessive force

58.Install hoist cables — the cable must be reeved through the sheaves according to the manufacturer's diagram

59.Verify electrical connections for load and angle limiters

60.Erect the boom using the gin pole or hydraulic lift cylinder

61.Install pendants — correct length according to the chart

62.Final verification — boom angle, cable tension, alignment

Critical point: Connecting pins must be spring pins or cotter pins, never replaced with ordinary bolts.

3.3 Telescopic Boom Assembly

The telescopic boom is generally assembled in a horizontal or slightly inclined position:

66.Verify crane level before any extension

67.Deploy the boom at the minimum recommended angle (typically 0–5°)

68.Extend sections one at a time, checking alignment

69.Verify limiters — the load limiter must be calibrated after each configuration change

70.Test operation — raise/lower, swing, extend/retract without load

Golden rule: Never extend the telescopic boom with a suspended load if the load chart prohibits it. Some configurations allow extension with a reduced load (tele-scoping under load), but only according to manufacturer specifications.

4. Counterweights and Balancing

4.1 Types of Counterweights

Type	Typical Mass	Advantages	Disadvantages
Steel counterweights (plates)	2–10 t per plate	Durable, precise	Heavy to handle
Concrete counterweights	3–15 t per block	Less expensive	Bulky
Hydraulic (retractable) counterweights	Integrated	No handling required	Limited mass
Trailer-mounted counterweights	10–30 t	High capacity	Requires trailer

4.2 Counterweight Installation

Counterweight installation procedure:

77.Consult the manufacturer's assembly chart to determine the number and position of counterweights

78.Install counterweights in the specified order (typically from inside to outside)

79.Verify locking — each counterweight must be mechanically locked

80.Never exceed the specified counterweight capacity

81.Document the installed configuration

Common error: Installing more counterweight than necessary to improve stability. This can actually reduce stability by increasing the overturning moment on the boom side (the additional counterweight increases total weight and may exceed the structural capacity of the slewing ring).

4.3 Calculating Required Counterweight

The required counterweight depends on the boom configuration and the maximum anticipated load:

Required counterweight (C) = (OM - SM_without_counterweight) ÷ Counterweight_distance

Where:

OM = Maximum anticipated overturning moment (load × radius)

SM_without_counterweight = Stabilizing moment of the crane without counterweight

Counterweight_distance = Distance from the counterweight centre of gravity to the tipping point

Example: A crane has a maximum overturning moment of 1200 kN·m. The stabilizing moment without counterweight is 600 kN·m. The counterweights are located 4 m from the tipping point.

C = (1200 - 600) ÷ 4 = 150 kN = 15 tonnes

5. Crane Disassembly

5.1 General Disassembly Procedure

Disassembly follows the reverse order of assembly, but with additional precautions:

95.Remove the load and position the boom at the recommended disassembly angle

96.Lower the boom onto horses if necessary

97.Remove counterweights in the reverse order of installation

98.Retract outriggers only after lowering the boom

99.Inspect components for wear or damage

100.Secure loose parts for transport

5.2 Lattice Boom Disassembly

Critical points when disassembling a lattice boom:

Lower the boom to the minimum angle (typically 0–5°) before removing pendants

Use horses to support boom sections

Remove pins in the reverse order of assembly

Mark sections to facilitate reassembly

Check cable condition — cables must be wound onto reels, never folded

5.3 Transporting Components

Component	Transport Method	Requirements
Boom sections	Flatbed truck	Minimum 4-point tie-down
Counterweights	Flatbed truck or trailer	Securing, weight verification
Cables	Cable reels	Protection from moisture
Pins and accessories	Boxes or containers	Inventory, corrosion protection
Outriggers	Secured to crane	Jacks retracted, mechanical locking

Transport regulations: The transport of crane components is subject to the Transportation of Dangerous Goods Regulations if loads exceed regulatory limits. Over-dimensional loads require special permits.

6. Pre-Use Checks

6.1 Pre-Assembly Inspection

Before assembly, the operator must inspect:

114.Structure — cracks, deformation, corrosion on boom sections

115.Pins and shafts — wear, deformation, presence of safety pins

116.Cables — broken wires, corrosion, deformation, diameter reduction

117.Sheaves — groove wear, free rotation

118.Hydraulic cylinders — leaks, damaged rods

119.Limiters — proper operation, intact seals

6.2 Post-Assembly Functional Test

After complete assembly, perform the following tests:

122.No-load hoist test — raise/lower the hook through the full travel

123.Swing test — full rotation left and right

124.Radius variation test — boom raise/lower

125.Limiter test — verify load and angle limiter activation

126.Emergency test — emergency stop, emergency descent

CSA Z150-16, Article 5.2 requirement: Every crane must undergo an inspection and functional test after each assembly, before being put into service.

6.3 Hoist Cable Inspection

The hoist cable must be inspected according to the following criteria:

Defect	Rejection Criteria
Broken wires	6 broken wires over a length of 6 diameters, or 3 broken wires in one strand
Diameter reduction	More than 7.5% reduction from nominal diameter
Corrosion	Visible corrosion with pitting
Deformation	Kinks, loops, crushing, elongation
Overheating	Discoloration due to heat

7. Environmental Conditions and Human Factors

7.1 Wind and Weather Conditions

CSA Z150-16, Article 4.4.2, requires work stoppage when:

Wind speed exceeds 32 km/h (20 mph) for normal operations

Wind speed exceeds 20 km/h for large surface area loads (panels, containers)

Wind speed exceeds the manufacturer's specified limit for the configuration in use

Wind load area calculation: Effective wind load (F) = 0.5 × ρ × V² × A × Cd

Where:

ρ = air density (1.225 kg/m³)

V = wind speed (m/s)

A = projected area (m²)

Cd = drag coefficient (0.8–1.2 depending on shape)

Rule of thumb: A 2 m × 6 m load (12 m²) exposed to a 40 km/h wind experiences a force of approximately 1.1 kN, which can represent 5–10% of the crane's capacity.

7.2 Temperature and Freezing Conditions

Extreme low temperatures: hydraulic cylinders can freeze, cables become more brittle

Frozen ground: may appear stable but thaws under outriggers

Cold wind: increases operator fatigue risk

Precipitation: ice on the boom increases weight and wind exposure

7.3 Human Factors

The human factor is responsible for more than 80% of incidents. The main factors:

151.Fatigue — assembly operations are physically demanding

152.Production pressure — never compromise safety to save time

153.Communication — use a qualified signal person, two-way radios

154.Competence — assembly must be supervised by a qualified person

155.Independent verification — a second set of eyes to check critical connections

8. Regulatory and Standards Requirements

8.1 Applicable Canadian Standards

Standard	Title	Main Content
CSA Z150-16	Safety of Mobile Cranes	Design, operation, and maintenance requirements
CSA Z248-17	Tower Cranes	Rules for tower cranes (if applicable)
CSA B149.1	Natural Gas and Propane Installation Code	If the crane operates on propane
Canadian Electrical Code, Part I, Chapter V	Electrical Safety	Power line clearances
Canada Occupational Health and Safety Regulations (Part II of the Canada Labour Code)	General requirements	Employer and employee obligations

8.2 Operator Obligations per CSA Z150-16

The operator must:

161.Verify inspection and maintenance certificates for the crane

162.Perform a daily inspection before use

163.Consult the manufacturer's manual for assembly procedures

164.Never exceed the rated capacity shown on the load chart

165.Report any defects to their supervisor immediately

166.Refuse to operate if safety conditions are not met

8.3 Required Documentation

Document	Content	Retention
Manufacturer's manual	Assembly procedures, load charts	On board the crane
Inspection log	Daily, weekly, annual inspections	Minimum 3 years
Annual inspection certificate	Inspection by a qualified inspector	Posted in the cab
Lift plan	For critical lifts	On site
Work permit	Authorization to operate	On site

9. Emergency Procedures

9.1 Hydraulic Failure During Assembly

In the event of hydraulic failure during assembly:

172.Do not attempt repairs under load

173.Lower the load using the emergency descent system

174.Secure the boom with mechanical supports

175.Evacuate the area under the load

176.Contact the supervisor and maintenance service

9.2 Imminent Overturn

If the crane begins to tip:

179.Lower the load immediately if possible

180.Reduce the radius (retract the boom)

181.Evacuate the area — do not attempt to save the crane

182.Shut off the engine and engage the swing brake

183.Call for emergency services if there are injuries

9.3 Power Line Contact

In the event of power line contact:

186.Stay in the cab — do not get out

187.Move the boom away from the line if possible

188.Alert authorities — have the power shut off

189.Only exit after confirmation that the power is off

190.If the cab is on fire: jump clear of the crane, feet together, avoiding simultaneous contact with the crane and the ground

10. Load Charts and Configurations

10.1 Understanding the Load Chart

The load chart indicates the maximum capacity for each configuration. Items to check:

194.Boom length — each added section changes capacity

195.Boom angle — capacity increases with angle

196.Radius — horizontal distance from the centre of rotation to the hook

197.Counterweight — capacity depends on installed counterweight

198.Outriggers — deployed or retracted

199.Fly jib — installed or not

10.2 Simplified Load Chart Example

50 t crane, outriggers deployed, full counterweight:

Radius (m)	10 m Boom	20 m Boom	30 m Boom
3	50.0 t	35.0 t	25.0 t
5	35.0 t	28.0 t	20.0 t
8	22.0 t	20.0 t	15.0 t
10	16.0 t	15.0 t	12.0 t
15	—	8.0 t	7.0 t
20	—	4.0 t	4.0 t

Interpolation: For a radius of 7 m with a 20 m boom, the capacity is between 28 t (at 5 m) and 20 t (at 8 m). Linear interpolation: 28 - [(7-5)/(8-5)] × (28-20) = 28 - 5.33 = 22.67 t.

10.3 Capacity Reduction Factors

Condition	Reduction Factor
Wind > 20 km/h (large surface area load)	20–30%
Wind > 32 km/h	Work stoppage
Uneven ground (> 1%)	Prohibited
Outriggers partially deployed	Per manufacturer's chart
Temperature > 40 °C	10% reduction
Load with side wind	Reduction based on surface area

11. Communication and Signaling

11.1 Standard Hand Signals

Hand signals must follow CSA Z150-16, Annex B:

Signal	Description
Hoist load	Forearm vertical, index finger pointing up, circular motion
Lower load	Forearm vertical, index finger pointing down, circular motion
Swing	Arm horizontal, index finger pointing in direction of swing
Travel	Arm bent, palm up, motion toward the body
Stop	Arm horizontal, palm down, abrupt motion
Emergency stop	Both arms crossed above the head

11.2 Radio Communication

Use two-way radios on a dedicated channel

Confirm each command by repeating it

Use clear, standardized language

When in doubt, stop the operation

Summary

The assembly, installation, and disassembly of a mobile crane require rigorous technical mastery and strict compliance with Canadian standards. The essential points to remember:

217.Stability is based on moment balance — the minimum safety factor is 1.5 per CSA Z150-16

218.Leveling must be within 1% in all directions

219.Cribbing is mandatory on non-concrete ground — calculate ground bearing pressure

220.Counterweights must be installed according to the manufacturer's chart — never exceed specifications

221.Boom assembly follows a precise sequence — pins must never be forced

222.Post-assembly checks are mandatory — inspection and functional test before service

223.Wind limits operations — 32 km/h maximum, 20 km/h for large surface area loads

224.Electrical clearances are defined by the Canadian Electrical Code, Part I, Chapter V, Rule 8-200

225.Documentation must be complete and current — manual, logs, certificates

226.Communication is essential — standardized signals, radios, qualified signal person

Common Pitfalls to Avoid

228.Confusing overturning moment and stabilizing moment — the overturning moment is the product of the load and its horizontal distance, not vertical.

229.Forgetting the impact factor — during hoisting, the dynamic load can be 10–25% higher than the static load.

230.Neglecting soil bearing capacity — apparently stable ground can settle under outriggers. Always calculate ground bearing pressure.

231.Installing too much counterweight — this can damage the slewing ring and reduce stability in certain configurations.

232.Using ordinary bolts to replace boom pins — this is prohibited and dangerous.

233.Forgetting to verify limiters after assembly — limiters must be calibrated for each configuration.

234.Disassembling the boom without horses — the boom can deform under its own weight.

235.Ignoring wind conditions — wind speed must be measured at boom height, not at ground level.

236.Not checking underground utilities — a gas line punctured by an outrigger can cause an explosion.

237.Confusing radius and boom length — radius is the horizontal distance, not the boom length.

238.Forgetting the human factor — fatigue and production pressure are major causes of incidents.

239.Not documenting configurations — each assembly configuration must be recorded for future reference.

240.Using non-standardized signals — only CSA Z150-16 signals are accepted.

241.Not checking the boom angle after assembly — the angle directly affects capacity.

242.Skipping the daily inspection — the pre-use inspection is mandatory and non-negotiable.