4 Types of Container Cranes

What are 4 Types of Container Cranes?

Dafang Container cranes have 4 common types: Rubber Tyre Container Crane(RTG Crane), Rail-mounted Container Crane(RMG Crane), Ship-to-shore Quay Crane(STS crane) and Container Straddle Carrier. These massive container handling equipment work across ports and yards to ensure stable and fluent operation.

Henan Dafang Heavy Machine Co Ltd. has been manufacturing and exporting container cranes for over 20 years. To better use container gantry cranes and improve working efficiency, it is essential to break down their core components, see the differences among them and see how they work together to safely and quickly lift, move, and stack heavy containers.

RTG Container Stacking Crane

Lifting Capacity: 35-70 ton
Span: 20-26 Meters
Lifting Height: 15-20 Meter
Hoisting Mechanism: Electric Trolley

RMG Container Port Crane

Lifting Capacity: 35-50 ton
Span: 20-35 Meters
Lifting Height: 15-18.5 Meter
Hoisting Mechanism: Electric Trolley

STS Container Dock Crane

Lifting Capacity: 35-75 ton
Lifting Speed: 50-90 m/min
Gantry Traveling Speed: 45 m/min
Certificate: CE/ISO
Boom Outreach: 10-45 Meters

Container Straddle Carrier

Lifting Capacity: 10-50 ton
Lifting Height: 10-13 m
Span: 18-35 Meters
Certificate: CE/ISO
Work Duty: A5-A8

Differences Among RTG/RMG/STS/Straddle Carrier

In port container handling, RTG, RMG, STS, and Straddle Carrier serve distinct roles with key differences. Rubber-tyred Gantry Cranes offer mobility for flexible yard stacking, ideal for medium-scale terminals. Rail-mounted Gantry Cranes use fixed rails for higher efficiency and lower energy use in large, dedicated yards. Ship-to-Shore Cranes specialize in loading/unloading containers between ships and lands. Container Straddle Carriers combine stacking and short-distance transport, suiting small terminals needing all-in-one mobility. Each excels in specific tasks—from ship-to-yard transfer to yard stacking—boosting port operational efficiency and cost.

1. Key Performance Parameters

Parameter	RTG Crane	RMG Crane	STS Crane	Straddle Carrier
Lifting Capacity	35-70t	35-50t	35-75t	10-50t (single gantry); Max 80t (double gantry)
Stacking Height	4-5 container layers	5-6 container layers	/	1-over-1 to 1-over-3 layers
Movement Freedom	Rubber tyres for full yard	Fixed rail lines	Quay rail lines	Rubber tyres for omnidirections
Span Range	20-26m (yard width)	20-35m (yard width)	10-45m (ship width)	18-35m (straddles 1-2 containers)
Working Radius	/	Dependent on cantilever design	Forward reach: 35-55mRear reach: 10-20m	Body coverage area
Energy Consumption	High (diesel)Medium (electric)	Low (stable electricity)	High (large motor)	Medium-high (load-dependent)
Core Advantage	Flexible relocation + multi-yard adaptation	High precision + low energy consumption	Ultra-large span + high lifting	Direct straddling + integrated transport/stacking
Key Limitation	Tire wear + low positioning accuracy	Rail constraint	Fixed-position operation	High ground load requirement (≥15t/㎡)

2. Basic Frame Comparison

Parameter	RTG Crane	RMG Crane	STS Crane	Straddle Carrier
Overall Structure	Double legs + box girder	Double legs + box girder	Gantry + forward boom + rear tie rod	Portal frame (single/double)
Support Method	8 heavy rubber tires, free-yard movement	16-24 steel wheels, fixed-rail operation	Leg-supported, travels along quay rails	6-8 large-diameter tires (1.2-1.5m), omnidirectional travel
Main Beam Structure	Box girder (smaller span, usually no cantilever)	Large-span box girder (optional cantilever)	Single/double box/truss structure	Portal frame (12-16m span)
Stability Design	Tires + balance counterweight	Fixed rail (high stability)	Rear tie rod + counterweight system	Low center of gravity + straddle structure

3. Hoisting & Spreader System

Component	RTG Crane	RMG Crane	STS Crane	Straddle Carrier
Hoisting Drive	Constant-power vector closed-loop control	Single/double drum + variable-frequency motor	Dual winch + wire rope	Hydraulic lifting system
Spreader Type	Standard container spreader	Standard container spreader	Telescopic spreader (20’/40’ compatible)	Bottom twistlock spreader
Anti-Sway Device	Torque anti-sway system	Bidirectional flexible resistance + laser positioning	Mechanical + electronic dual anti-sway	Hydraulic balance system
Lifting Speed	10-18m/min	13-20m/min	30-50m/min (loaded)	8-15m/min

4. Travel & Drive System

System	RTG Crane	RMG Crane	STS Crane	Straddle Carrier
Travel Mode	Tire-based free travel (360° steering)	Fixed-rail travel	Travels along quay rails (gantry)	Omnidirectional (longitudinal/transverse/diagonal)
Drive Type	Traditional: diesel generator; New: cable reel/trolley line	Three-phase AC 380V (trolley line)	Electric (trolley line/cable reel)	Diesel-hydraulic / full electric (lithium battery)
Positioning Accuracy	±50mm	±5mm	±3mm	Manual operation (lower accuracy)
Typical Speed	Gantry: 20-40m/minTrolley: ~50m/min	Gantry: 40-60m/minTrolley: ≥70m/min	Gantry: 20-40m/minTrolley: 120-200m/min	Travel: 10-25km/hOperation: 5-10km/h

Container Cranes Features & Application

1. RTG Crane

Core Features: Tire travel + gantry structure, balanced flexibility/stability
Steering Feature: 0-90° in-situ steering, adaptable to multi-area operations
Application Scenario: Medium-small ports, yards requiring flexible relocation

2. RMG Crane

Core Features: Fixed rails + large-span gantry, excellent stability
Structural Advantage: Modular design, multi-machine collaborative operation
Application Scenario: High-density automated yards, railway container hubs

3. STS Crane

Core Features: Tall gantry + long forward boom, designed for ship-to-shore handling
Unique Mechanism: Luffing system (boom can lift to clear ships)
Application Scenario: Quay front of container terminals, direct ship loading/unloading

4. Straddle Carrier

Core Features: Portal frame + bottom spreader, directly straddles containers
Structural Innovation: No rails required, travels freely on flat ground
Application Scenario: Yard horizontal transport + stacking, railway yard short-haul