Advantages and Disadvantages of Fender Types

Fenders using elastomeric units

1. Hollow cylindrical (diametrically loaded) fenders

a) Advantages:

1) economical;
2) easy to install or replace individual units;
3) may be mounted to give cover over a large vertical range.

b) Disadvantages:

1) susceptible to damage by surging motion of vessel;
2) long length necessary to spread reactive force;
3) larger than other elastomeric units to absorb same energy.

2. Cylindrical floating (diametrically loaded) fenders

a) Advantages:

1) economical;
2) one unit covers full tide range.

b) Disadvantages:

1) susceptible to damage by surging motion of vessel;
2) no resistance to vessel surge;
3) can roll up face of berth unless restrained.

3. V-shaped fenders

a) Advantages:

1) easy to install or replace individual units;
2) low reaction and high energy absorption with constant reaction over part of deflection range.

b) Disadvantage:

1) only cover a small tidal range unless upper and lower rows of fenders provided.

4. Buckling column fenders

a) Advantages:

1) easy to install or replace individual units;
2) low reaction and high energy absorption with constant reaction over part of the deflection range.

b) Disadvantages:

1) has to be used with fender frame;
2) may require horizontal chains to resist longitudinal friction force.

5. Rectangular or square section solid strips and D bore fenders

a) Advantage:

1) simple design, easy to install and replace.

b) Disadvantages:

1) generally low energy capacity;
2) long length necessary to spread reactive force.

6. Fender piles

a) Advantage:

1) if closely spaced they provide good protection for berths in large tidal ranges, especially where small vessels are to be accommodated.

b) Disadvantages:

1) require suitable geotechnical conditions;
2) replacement of damaged piles in front of berth usually necessitates temporary restrictions on berth usage.

7. Floating pneumatic fenders

a) Advantages:

1) large energy capacity;
2) low reactive force;
3) can adapt to curved hull surfaces and angled berthing;
4) full tidal range can be covered with single unit;
5) simple to install and remove; units can be moved from berth to berth as need arises.

b) Disadvantages:

1) large diameter keeps vessel further from the cope than other types which leads to:
i) greater first costs for container cranes, shiploaders and similar equipment;
ii) heavier bogie loads for container cranes, shiploaders and similar equipment;
iii) increased operation cycle times for container cranes, shiploaders and similar
equipment;
2) require large beating area that may have to extend above general level of berth deck;
3) can roll up face of berth if not suitably restrained;
4) require secondary protection against tearing and puncturing by protrusions from ship’s hull.

8. Foam filled floating fenders

a) Advantages:

1) large energy capacity;
2) low reactive force;
3) can adapt to curved hull surfaces and angled berthing;
4) full tidal range can be covered with a single unit;
5) simple to install and remove; units can be moved from berth to berth as the need arises;
6) will not sink immediately or collapse, if punctured.

b) Disadvantages:

1) large diameter keeps vessels further from the cope than most other types;
2) require large bearing area that may have to extend above general level of berth deck;
3) can roll up face if not suitably restrained.

9. Fixed pneumatic fenders

a) Advantages:

1) large energy capacity;
2) low reactive force;
3) little loss of efficiency with angled berthing and adapts to curved hull surface;
4) easy to install and replace;
5) several fenders may be coupled to common fender frame to give larger capacity unit.

b) Disadvantages:

1) require a protective cap to reduce friction with ship’s hull;
2) can be torn or punctured by protrusions from ship’s hull.