Yokohama fender, also known as pneumatic fender, is a common floating fender. It mainly uses air as the medium and uses compressed air to absorb impact energy. It makes the ship more flexible and soft when berthing, so as to achieve the effect of anti-collision.
Hengyang are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.
Basic Composition of Yokohama Pneumatic Fenders
The Yokohama pneumatic fenders are made of synthetic cord reinforced rubber sheets with compressed air inside with an initial pressure of 50kpa or 80kpa, allowing them to float on the water and act as shock absorbers between the two boats. According to ISO-1:, the pneumatic fender consists of the following parts:
1. Outer rubber layer
The rubber layer covering the outer side of the fender is used to protect the fender frame material and the inner rubber from external damage or wear.
2. Inner rubber layer
The rubber layer on the inner wall of the fender is used to prevent gas leakage and maintain the air pressure of the fender.
3. Cord rubber layer
The baked skeleton material consists of hanging rubber cord fabric.
4. Winding ring
A steel ring placed at one (or both) ends of the fender is used to fix the end of the cord fabric.
5. End flange
The metal parts at both ends of the fender can be fitted with inflatable valves and safety valves.
Advantages of Yokohama Pneumatic Fenders
Yokohama pneumatic fenders have been widely used in tankers, container ships, yachts, offshore platforms, large docks, military ports, large terminals, etc.
If you are looking for more details, kindly visit Shield Type Steel River Dam.
Compared with the traditional elastic rubber fenders, Yokohama fenders have the following advantages:
- Large impact energy absorbed and small impact resistance to the ship.
- Easy to install.
- Good elasticity and no deformation under pressure.
- Lightweight, practical and economic.
Performance of Yokohama Pneumatic Fenders
Selection of Yokohama Pneumatic Fenders
When ship owners choose fenders, sometimes the factors considered are not comprehensive enough, and they often feel very troublesome. The following example can help solve this problem.
Examples of fender options for small and medium-sized ships
Examples of fender options for large ships
Why Are Pneumatic Fenders Also Called Yokohama Fenders?
What is the difference between pneumatic fenders and Yokohama fenders? Pneumatic fenders or Yokohama fenders are actually two names for the same product. Pneumatic fenders are air-filled rubber fenders (hence the name pneumatic fenders). This type of rubber fender was first developed by Yokohama in . Since then, it has become a widely used fender in shipping and ports.
Yokohama fenders are used for berthing ships in (sea) ports as well as the ships themselves. On ships, fenders are often used in situations where a ship (such as a bunkering vessel) approaches to transfer cargo from one ship to another. In addition, pneumatic fenders are also commonly used in offshore engineering or dredging industries.
Because pneumatic fenders are filled with air, the fenders float like foam or foam-filled fenders. So what is the difference between Yokohama pneumatic fenders and foam filled fenders? Please refer to: The difference between Yokohama pneumatic fenders and foam filled fenders.
Yokohama Pneumatic Fender Types
Yokohama pneumatic fenders are available in diameters ranging from 300 mm to mm and lengths ranging from 500 mm to mm, as well as special sizes. All sizes are available with sling type or heavy-duty chain and tire mesh.
It is unlikely that you will find proper performance data for tires used as fenders, simply because they are not designed to be fenders. The tires used either on floating fenders (eg Yokohama or foam-filled) are used truck or aircraft tires. The tires typically used on berths can be any used tyre available. In Norway they normally use truck or tractor tires. Unless actual performance tests are performed on tires, there is no reliable data available on energy absorption, reaction force, deflection and/or hull pressure. The variety of tires available is simply too large to generalise performance or to estimate average values. Furthermore, tires are often used in layers (2 or more rows of tires stacked), rather than as single pieces. Which means the interaction between 2 or more stacked tires need to be taken into account as well.
Tires are not fenders. Not intended to be used as them and not particularly suitable for the task. The main reason they are used, is that they are cheap compared to any decent foam, fixed rubber and/or pneumatic fender. The only reasons to use them on pneumatic or foamfilled fenders, is to protect the fender skin (mainly applicable for pneumatic fenders) and/or to increase stand-off at low cost (primarily applicable to foam fenders).
I guess Mike has a point: if you want reliable data, you will need to put tires to the test. Large tires can only be tested at a few facilities. LeHigh University has a large test bench. Fender manufacturers like Marine Fender International (possibly) and Maritime International (certain) may have test facilities as well. Be prepared to pay a substantial amount of money though: a test procedure as specified in the PIANC report can easily set you back 10 - 15 K USD. In my book, that is money wasted, since tires are not selected for their performance, but merely since they are cheaper than the alternatives, readily available (from stock), do not require proper engineering and are typically installed based on rules of thumb/experience. As long as no captain complains about damage to the vessel,it probably is ok.
I assume that in general performance figures will turn out to be horrible. Relatively low energy absorption (there is not much material available for deflection compared to a proper fender) and high reaction force as the tyre is deflected on its most sturdy part: the heavily reinforced treat region. Which is not very forgiving to a delicate ship's hull. Using several layers of tires, rather than a single one, will improve the performance figures though. But compared to a proper designed fender system, it will be mediocre. Coefficient of friction probably will be high as well. Same as hull pressure, as the contact area is (relatively) small and not evenly distributed.
@Hydromarine: though ISO is indeed good bedtime reading, it will not answer the question, since it applies to pneumatic fenders, not to tires used as fenders. PIANC and are probably more usefull. Even though they also do not recognise tires as fenders (or even substitutes).
The only really proper fenders made from tires are the ones manufactured by Schuyler.