Crawler Crane Rack Support Cylinder | EP-HCYY11112022 Model

Crawler crane rack support cylinder EP-HCYY11112022 deploys the outrigger rack structure that widens the crane footprint during heavy lifts — extending the effective track width by 2–4 metres per side. Bore Φ70 mm, rod Φ50 mm, stroke 1,237 mm at 20 MPa (30 MPa max). The 71.4% rod ratio balances push force for deployment with column strength for holding under side-loading from wind and dynamic load swings. Weight 48 kg, installation distance 1,437 mm. Folds inward for transport, extends outward for lifting. Korea Ever-Power. ISO 9001.
Artikelnummer: 408f1035d910 Kategorie:

Mobile Machinery Hydraulic Cylinder

Crawler Crane Rack Support Cylinder
EP-HCYY11112022 · Φ70mm · Stroke 1,237mm · 20 MPa · 48 kg

The cylinder that extends and positions the outrigger rack structure on lattice boom crawler cranes. The rack support system widens the crane's footprint during lifting operations — increasing stability by distributing the ground bearing pressure across a larger area. At 48 kg with a 1,237 mm stroke, this cylinder deploys the opening rack from its folded transport position to its fully extended working configuration.

Φ70Bore
1,237mmStroke
20 MPaWorking Pressure
30 MPaMax Pressure
48 kgWeight

Technical Specifications

Crawler Crane Rack Support Cylinder | EP-HCYY11112022 Model Dimension Drawing▲ Dimension Drawing

Parameter Specification
Product Name Crawler Crane Rack Support Cylinder
Cylinder Model EP-HCYY11112022
Bore (D) Φ70 mm
Rod (d) Φ50 mm
Stroke (S) 1,237 mm
Installation Distance (L) 1,437 mm
Working Pressure 20 MPa
Maximum Withstand Pressure 30 MPa
Weight 48 kg
Application Lattice Boom Crawler Crane
Crawler Crane Rack Support Cylinder | EP-HCYY11112022 Model▲ Crawler Crane Rack Support Cylinder | EP-HCYY11112022 Model

How Rack Support Cylinders Stabilise the Crawler Crane

Crawler crane hydraulic cylinder positions

Large crawler cranes operate near their tipping limits during heavy lifts. The opening rack support system extends outward from the crane's tracks, creating a wider base of support. The rack support cylinder pushes the rack structure from its folded position (for transport) to its deployed position (for lifting), adding several metres to the crane's effective track width.

The 1,237 mm stroke provides the full range of rack deployment — from fully folded to fully extended. The Φ70 bore at 20 MPa produces approximately 77 kN of extension force, sufficient to deploy the rack structure and hold it rigidly in position against the overturning moments generated during crane operation.

The 71.4% rod-to-bore ratio (Φ50/Φ70) provides a balance between push force (for deployment) and column strength (for holding the rack in position under side-loading). The cylinder must resist lateral forces from wind, ground slope, and dynamic load swings. Browse the full mobile machinery hydraulic cylinder range.

Rack Support: The Stability Margin That Enables Heavy Lifts

Transport vs Lifting Footprint

For road or site transport, the racks fold inward — the crawler crane fits within its track width. For lifting, the racks deploy outward — typically adding 2–4 metres per side. The cylinder makes this transition hydraulic and controlled.

Ground Bearing Pressure Distribution

By widening the base, the rack reduces the ground bearing pressure — preventing the crane from sinking into soft ground. On construction sites with poor soil conditions, the rack support is essential for safe crane operation.

Front and Behind Variants

The crawler crane uses multiple rack support cylinders — front and rear, left and right. The EP-HCYY11112022 is one variant; related models (EP-HCYY11112024, 26) serve front and behind positions with different mounting geometries.

Crawler Crane Rack Support Cylinder dimensions

Crawler Crane Cylinder Family

Korea Ever-Power manufactures 8+ cylinder models for lattice boom crawler cranes — luffing, rack support, frame support, boom angle, and supplementary bracing cylinders:

EP-HCYY11112018

Luffing Cyl. Φ280, 1155kg

EP-HCYY11112022 ← this product

Rack Support Cyl. Φ70, 48kg

EP-HCYY11112023

Frame Support Cyl. Φ140, 123kg

EP-HCYY11112021/24/25/26/27

Boom Angle + Additional Support (5 models)

Why Choose Korea Ever-Power

Korea Ever-Power is a professional hydraulic cylinder manufacturer and supplier, specialising in forklift hydraulic cylinders, aerial work vehicle cylinders, mobile machinery cylinders, offshore cylinders, and industrial engineering cylinders. Our production facilities are equipped with composite machining centres, multi-station welding robots, automated assembly lines, specialised cylinder testing machines, and a dedicated quality inspection area — ensuring every cylinder meets OEM-grade performance standards.

Korea Ever-Power hydraulic cylinder manufacturing facility

Korea Ever-Power forklift tilt cylinders are manufactured to the same specifications and quality standards as original equipment cylinders fitted to major forklift brands worldwide. Every cylinder is 100% hydrostatic pressure tested, dimensionally inspected, and shipped with a test certificate and seal kit. Contact the Korea Ever-Power team for pricing and lead time.

Hydraulic cylinder production

Frequently Asked Questions

How many rack support cylinders does a crawler crane use?

Typically 4–8, depending on the crane model and rack configuration — front left, front right, rear left, rear right, plus possible intermediate positions. The EP-HCYY11112022 is one variant; consult Korea Ever-Power for the complete set for your crane model.

What is the difference between rack support and frame support?

Rack support cylinders deploy the outrigger rack structure (widening the base). Frame support cylinders (EP-HCYY11112023) are structural members that brace the main crane frame. Both contribute to stability but serve different structural functions.

Can the crane operate without the rack deployed?

Modern crawler cranes have load charts for both rack-deployed and rack-folded configurations. Operating without the rack reduces the maximum allowable load and radius. The crane's load moment indicator (LMI) adjusts automatically based on rack deployment status.

Does Korea Ever-Power supply the complete crawler crane cylinder set?

Yes — luffing, rack support, frame support, boom angle, and additional bracing cylinders are all available. Also available: truck crane cylinders (EP-HCYY11112013–17). Browse the mobile machinery hydraulic cylinder range.

What Our Customers Say

★★★★★May 2026

"We replaced all 4 rack support cylinders on our 200-tonne crawler crane. The EP-HCYY11112022 deployed smoothly on first extension — the 1,237 mm stroke matches the original specification exactly. Crane passed its load test at full rack extension."

M. Petersen — Crane Operations Manager, Denmark

★★★★☆Jan 2026

"At 48 kg, the rack support cylinder is manageable for a 2-person team with a chain hoist. Good quality chrome, tight seals. Cost approximately 35% below OEM price."

C. Nakamura — Equipment Buyer, Japan

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