Views: 323 Author: NANJING TAIDUN Publish Time: 2026-10-12 Origin: Site
Content Menu
● What Is a CTN Type Pneumatic Fender?
● What Is a Sling Type Pneumatic Fender?
● Direct Comparison: CTN Type vs Sling Type
● The Weight Problem: Why Lightweight CTN Is Changing the Game
>> The Lightweight CTN Solution
● Real-World Decision Framework: Which Type for Which Application?
● Application Case Studies: CTN and Sling in the Field
>> CTN Type Success: Bulk Cargo Terminal, Southeast Asia
>> Sling Type Success: Naval Base, Northern Europe
● The OEM Perspective: Manufacturing Both Types to Specification
>> Quality Control for Both Types
● Specification Checklist for OEM Buyers
● Conclusion: There Is No Universal "Best" Type
● Frequently Asked Questions (FAQ)
>> 1. What is the fundamental difference between CTN Type and Sling Type pneumatic fenders?
>> 2. Which type is better for ship-to-ship (STS) transfer operations?
>> 3. Can Sling Type fenders be used on rough concrete quay walls?
>> 4. What is the weight difference between CTN and Sling Type fenders?
>> 5. Are both types ISO 17357-1:2014 compliant?
>> 6. How does NANJING TAIDUN support OEM partners for both fender types?
Introduction: One Decision, Two Very Different Outcomes
When specifying pneumatic rubber fenders for a port project or OEM product line, one question consistently determines long-term performance and maintenance costs: CTN Type or Sling Type?
Both are ISO 17357-1:2014 compliant pneumatic fenders. Both absorb berthing energy through compressed air. But they are engineered for fundamentally different operating environments.
As an OEM manufacturer at NANJING TAIDUN MARINE EQUIPMENT ENGINEERING CO., LTD, we have produced both CTN Type and Sling Type pneumatic fenders for partners across 80+ countries. This guide provides the engineering comparison that procurement teams and port engineers need—without marketing language.
CTN stands for Chain-Tire-Net. This is the traditional Type I pneumatic fender configuration defined in ISO 17357-1:2014.
The CTN Type fender starts with a standard pneumatic rubber body—multiple layers of synthetic-tire-cord reinforced rubber surrounding a pressurized air chamber. What distinguishes it is the external protection system:
- Galvanized steel chains: Horizontal and vertical chains form a lattice around the fender body
- Used tires: Aircraft or truck tires are threaded onto the chain lattice, providing sacrificial wear surfaces
- Rubber sleeves: Cover the chains to prevent direct chain-to-rubber abrasion
The result is a heavyweight, highly protected fender designed to survive contact with rough concrete quay walls, sharp pier edges, and abrasive vessel surfaces.
The Sling Type pneumatic fender is the Type II configuration under ISO 17357-1:2014.
Sling Type fenders are essentially body-only pneumatic fenders. They have:
- No chain-tire net surrounding the rubber body
- Reinforced flange areas at each end with integrated lifting eyes (towing lugs)
- Thicker outer rubber layer to compensate for the absence of external protection
The fender is deployed by attaching chains or wire ropes to the lifting eyes at each end and suspending it in position.
| Feature | CTN Type (Chain-Tire-Net) | Sling Type |
|---|---|---|
| ISO Classification | Type I | Type II |
| External Protection | Chain net + tires + rubber sleeves | None (thicker outer rubber only) |
| Weight (3300×6500mm, 50kPa) | ~4,154 kg | Significantly lighter |
| Weight (4500×9000mm, 50kPa) | ~8,565 kg | Significantly lighter |
| Hull Damage Risk | Moderate (chains can scratch painted hulls) | Minimal (no metal contact) |
| Rubber Body Protection | Excellent (sacrificial tire/chain layer) | Limited (direct rubber exposure) |
| Deployment Speed | Slower (heavy, requires careful handling) | Fast (lightweight, easy to mobilize) |
| Primary Use Cases | Rough quay walls, STS transfer, harsh environments | Sensitive hulls, naval vessels, rapid deployment |
| Maintenance Burden | Higher (chain corrosion, tire replacement) | Lower (visual inspection, rubber repair) |
| Typical Lifespan | Longer for rubber body (protected) | Shorter without protection |
Traditional CTN fenders have a well-known operational challenge: weight.
A standard 3300×6500mm CTN fender at 50 kPa weighs approximately 4,154 kg. The same fender in 4500×9000mm configuration reaches 8,565 kg.
This weight creates real problems:
- Difficult mobilization with small cranes
- Higher shipping costs (weight-based)
- Increased injury risk during manual handling
- Loading/unloading challenges at ports without heavy lifting equipment
Industry leaders have developed lightweight CTN constructions that replace heavy steel chains with synthetic chains (strength equivalent to 200 kN steel chain, but only 0.65 kg/m) and substitute tires with rubber hose pipes (OD 200mm).
Weight comparison for 3300×6500mm, 50 kPa:
| Configuration | Weight | Weight Saving |
|---|---|---|
| Standard CTN | 4,154 kg | — |
| Lightweight CTN | 2,240 kg | 1,914 kg (46%) |
Critical insight: GEA, reaction forces, and product performance remain unchanged.
This means OEM partners can offer the protection benefits of CTN with dramatically improved logistics and handling characteristics.
1. Berthing against rough concrete quay walls — Tires absorb abrasion that would destroy unprotected rubber
2. Ship-to-Ship (STS) transfer operations — CTN provides protection during multi-vessel contact
3. Harsh environments with debris — Chains and tires deflect sharp objects
4. Long-term permanent installations — Protected rubber body extends service life
5. Budget optimization for high-abrasion sites — Sacrificial tires are cheaper to replace than fender bodies
1. Protecting vessels with sensitive hull coatings — No metal chain contact with hull
2. Naval and cruise applications — Appearance and hull preservation matter
3. Rapid deployment requirements — Lightweight design enables fast mobilization
4. Temporary or emergency berthing — Easy to deploy, retrieve, and relocate
5. Areas with large tidal ranges — Sling type maintains clearance between hull and structure
A major coal export terminal in Indonesia required fenders for berthing Panamax and Capesize bulk carriers against a concrete quay wall with exposed aggregate surface. Initial specification called for Sling Type fenders for hull protection. After six months, Sling Type fenders showed severe abrasion damage—rubber loss exceeded 15% of body thickness.
Solution: Switched to CTN Type fenders. The sacrificial truck tires absorbed the abrasion, and after 24 months, the rubber bodies showed minimal wear—only tires needed replacement.
Outcome: Lower total cost of ownership despite higher initial CTN weight and cost.
A naval facility required fenders for frigate and submarine berthing. The client's primary concern was hull coating integrity—any metal contact could compromise sonar-domes and stealth coatings.
Challenge: CTN Type was rejected due to chain-contact risk.
Solution: Sling Type fenders with reinforced flange areas and thicker outer rubber. Deployment used existing crane infrastructure rated for the lighter weight.
Outcome: Zero hull coating damage incidents over 18 months. Rapid deployment capability supported the base's operational tempo.
At NANJING TAIDUN, we manufacture both CTN Type and Sling Type pneumatic fenders under OEM agreements for international brands, wholesalers, and port equipment suppliers.
- ISO 17357-1:2014 compliant production processes
- 50 kPa and 80 kPa internal pressure configurations
- Sizes from 500×1000mm to 4500×12000mm (standard and custom)
- Third-party certification: CCS, BV, LR, TUV, SGS, INTERTEK, GL
- OEM branding: Private label, custom packaging, branded documentation
Every pneumatic fender—CTN or Sling—undergoes:
1. Dimensional verification against approved drawings
2. Initial internal pressure testing (50 kPa or 80 kPa ± tolerance)
3. Compression testing: Energy absorption and reaction force verification
4. Air tightness testing: Pressure decay monitoring
5. Material certification: Rubber compound and reinforcement cord documentation
6. Third-party witnessing (upon request): BV, SGS, ABS, LR, DNV
For CTN Type fenders, additional checks include:
- Chain galvanization thickness verification
- Tire condition inspection
- Rubber sleeve fit and integrity
When ordering CTN or Sling Type pneumatic fenders for your market, confirm these specifications:
| Parameter | Options | Notes |
|---|---|---|
| Fender Type | CTN (Type I) or Sling (Type II) | Specify application context |
| Size | Diameter × Length | Standard sizes or custom |
| Initial Pressure | 50 kPa (Pneumatic 50) or 80 kPa (Pneumatic 80) | Match vessel and berth requirements |
| Body Material | Synthetic-tire-cord reinforced rubber | Verify cord layer count |
| CTN Components | Chain type, tire type, sleeve specification | For CTN orders only |
| End Fittings | Lifting eyes, shackles, swivels | Specify material and coating |
| Certification | CCS, BV, LR, etc. | Confirm third-party witness requirements |
| Markings | OEM brand, product ID, pressure rating | Per your market requirements |
The CTN versus Sling decision is not about which fender is superior. It is about matching the fender type to the application.
CTN Type delivers maximum protection for the fender body in harsh, abrasive environments. The trade-offs are weight, hull-contact risk, and higher maintenance.
Sling Type delivers maximum hull protection and rapid deployment. The trade-offs are reduced fender body protection and shorter lifespan in abrasive conditions.
For OEM partners, the opportunity lies in offering both types—and knowing when to recommend each. A port authority that needs rough-quay protection should not be sold Sling Type fenders. A naval base concerned about stealth coatings should not receive CTN Type.
At NANJING TAIDUN MARINE EQUIPMENT ENGINEERING CO., LTD, we manufacture both types to ISO 17357-1:2014 standards, with the documentation and third-party certification that international OEM partnerships require.
[CTA]
Ready to specify CTN or Sling Type pneumatic fenders for your market?
Contact NANJING TAIDUN for OEM manufacturing support:
- Email: service@taidunmarine.com
- Website: www.taidunmarine.com
- Phone/WhatsApp: +86-18751950876
- Services: OEM manufacturing, custom dimensions, third-party certification coordination, export documentation
1. tradeKorea. "Pneumatic rubber fenders complaint with ISO17357:2014." [https://tradekorea.com/product/detail/P686818/]
2. IMPA Catalogue. "Fenders Rubber Pneumatic." [https://impa-catalogue.shipserv.com/23-rigging-equipment-general-deck-items/fenders/fenders-rubber-pneumatic]
3. Sakakibara, S. "Revision of ISO17357: Ships and Marine Technology, Floating Pneumatic Rubber Fenders." J-STAGE. [https://www.jstage.jst.go.jp/article/jinnavi/191/0/191_KJ00009702478/_pdf/-char/en]
4. Nanjing Taidun Marine Equipment Engineering Co., Ltd. Company Profile. [https://www.taidunmarine.com/]
CTN Type (Type I) fenders have an external protection system consisting of galvanized chains, used tires, and rubber sleeves. This sacrificial layer protects the rubber fender body from abrasion and sharp objects. Sling Type (Type II) fenders have no external net—only a reinforced flange area with lifting eyes and a thicker outer rubber layer. The trade-off is protection versus hull safety and weight.
CTN Type is generally preferred for STS operations because the chain-tire net provides protection during multi-vessel contact, and the sacrificial tires absorb abrasion from repeated fender-to-fender contact. Sling Type is used in STS when hull protection is the priority, but the rubber body may wear faster.
Not recommended without additional protection. Sling Type fenders have no sacrificial layer. Direct contact with rough concrete or exposed aggregate surfaces will cause accelerated rubber abrasion. In such applications, CTN Type is the appropriate choice.
For a 3300×6500mm, 50 kPa fender, CTN Type weighs approximately 4,154 kg, while Sling Type is significantly lighter (the exact weight depends on configuration). Lightweight CTN constructions reduce weight to approximately 2,240 kg—a 46% weight saving—while maintaining the same energy absorption and reaction force performance.
Yes. ISO 17357-1:2014 recognizes both Type I (CTN) and Type II (Sling) configurations. Compliance covers material requirements, performance verification (energy absorption, reaction force), dimensions, and testing procedures.
NANJING TAIDUN manufactures both CTN Type and Sling Type pneumatic fenders under OEM agreements. We provide:
- Manufacturing to ISO 17357-1:2014 standards
- Third-party certification coordination (CCS, BV, LR, TUV, SGS, INTERTEK, GL)
- Custom dimensions and configurations
- Private-label branding and export packaging
- Full documentation packages for international markets
