What are the common problems in the installation and maintenance of Yokohama fenders?

1. Inaccurate internal pressure control

   Operators ignore temperature correction when inflating fenders. Air pressure rises under sunlight and high ambient temperature, leading to actual pressure higher than rated P50/P80 value; low-temperature dockside inflation causes insufficient working pressure. Overinflation increases berth reaction force to overload pier structures; underinflation reduces energy absorption and brings hard impact damage to hulls.

2. Improper safety valve management for large-size fenders (≥2500 mm diameter)

   Safety valves are either blocked by dirt/corrosion or adjusted arbitrarily on site. The valve only releases pressure from sudden mechanical compression, yet many staff mistakenly rely on it to offset thermal pressure changes. Uncalibrated valves fail to protect the fender during extreme berthing compression.

3. Accepting products without complete ISO documents

   Installers use fenders without verifying serial numbers, test certificates and actual pressure grades, simply trusting product labels copied from old similar projects. Mismatched pressure grade is the most costly hidden problem, triggering long-term excessive reaction force on berth foundations.

1. Uneven installation of chain-tire protective nets: partial net tightening causes concentrated friction and local rubber wear; loose nets drop off during vessel contact and lose anti-abrasion protection.

2. Improper anchor chain slack setting: insufficient chain allowance cannot adapt to tidal water level fluctuation, making flanges bear persistent tensile load; excessive slack leads to fender drifting, tilting and oblique extrusion during berthing.

3. Irregular layout arrangement: uneven spacing of multiple fenders leads to partial fenders bearing most impact energy and premature local damage.

1. Over-tensioned guy chains/slings: cyclic tidal movement creates repeated pulling stress on end flanges and bead rings, causing hidden metal deformation even if the outer rubber looks intact.

2. Unmatched on-site hoisting equipment: improper lifting points damage flange structures during deployment and recovery.

3. Random temporary fixing points: unstable bollard connections make fenders shift violently under ship collision.

Fenders are installed without matching the hull curvature, resulting in partial contact. Local high hull pressure scratches the rubber surface and lowers the overall shock-absorbing performance of pneumatic fenders.

1. Irregular pressure inspection

   Many terminals cancel regular pressure testing due to cumbersome operation. Slow air leakage from tiny skin punctures or valve loosening cannot be detected in time, gradually weakening fender cushion capacity.

2. Superficial inspection only

   Most inspectors merely check the outer rubber appearance. After heavy berthing impacts, flange, bead ring and internal steel components may produce permanent deformation, which cannot be found via visual check and will lead to sudden fender failure later.

3. Neglected corrosion of metal accessories

   Shackles, swivels, anchor chains and sling fittings suffer saltwater corrosion in marine environments. Rust thinning or micro-cracks develop gradually without timely replacement, bringing risks of breakage during berthing.

4. Poor idle fender storage

   Unused fenders are exposed to long-term sunlight, seawater splashes or sharp objects. Rubber aging, cracking and puncture damage occur before formal use. Deflated fenders are also frequently folded sharply to form permanent creases inside the rubber liner.

1. Using P80 high-pressure fenders blindly for higher energy absorption, without recalculating the allowable reaction force of berth structures and hull pressure limits.

2. No targeted maintenance plan: applying the same inspection cycle for fixed net-type fenders and frequently moved sling-type fenders.

3. Confusing PIANC design guidelines with product certification; mistakenly believing PIANC-certified products eliminate routine detection obligations.

4. Delayed replacement of worn protective tires, nets and slings, aggravating fender body abrasion damage.

Oblique berthing over 15°, excessive vessel approaching speed, sharp hull attachments and floating debris will aggravate fender skin tearing and puncture damage, which is worsened if maintenance checks are not followed up promptly.