The word “bollard” was first reported use is from a Scottish newspaper in 1763 referencing a marine bollard, used at a dock to moor boats. The use of the word spread, and now mooring bollards are known to every English-speaking mariner. Marine mooring bollards provide a simple yet efficient method for fulfilling mooring requirements to allow safe securing of vessels next to jetties, wharves, berths and dolphins in ports and harbors.
Jier Marine can provide a wide range of cast iron or steel bollards in various specifications, grades and capacities in accordance to various international standards such as BS 6349 pt 4 and PIANC Guidelines.
The Design of Bollard
As there are several types of bollards, some of the following aspects are usually necessary to be considered in the type and size design of the berth:
1.Mooring patterns and line types, sizes and hawser or rope angles
2.Changes in draft during loading/unloading of the vessel
3.Wind and current forces
4.Swell, wave and tidal forces
5.The space and installation surface available for the bollard
6.Other abnormal environmental loadings
Mooring loads should be calculated considering yield strength in specific condition with different standard all over the world for different project application.
The Durability of Bollard
Bollards need be safety critical components and resistance to kinds of physical and corrosive environments, there are several combinations of options for bollards’ mechanical performance with different types materials and corrosion protection coatings as below chart:
Standard available coatings include (uncoated, zinc oxide primer or high performance epoxy). As high performance epoxy or other specified paint system for request in a choice of colors and thicknesses. The bollard bodies can also be supplied with Hot Dip Galvanizing (HDG) on a special request basis. Wear and abrasion from ropes means paint coatings need regular maintenance. Ductile iron bollards are far less susceptible to corrosion than cast steel bollards, which can rust quickly and will need frequent painting to retain full strength.
The Installation of Bollards
Bollards must be installed correctly to maintain a long and trouble-free service life. Once the grout has cured to full strength, anchors can be tightened to the design preload. A thread loosening compound is frequently applied to allow future removal for replacement. Where possible, recessing the bollard in the concrete is more beneficial than surface mounting.
Fixing options for bollards include:
5.Structural Steel Mounted