special boarding ladder for port

The boarding ladder is an equipment for people boarding and disembarking safely and favourably during oil tanker operating at modern size oil dock. The conventional boarding equipment accomplish the purpose by accommodation ladder of tanker.during the development of oil dock, latter-day size oil dock, special naked pier, dock surface is discontiguous and too high in elevation, the ship bump and drift continually and sreongly during operation. Distance between the shipboard in berth and the edge of dock is too long because of the large fender, in this condition, it is difficult to settle the contact between ship and dock with accommodation ladder so as to accelerate loading work of tanker and ensure that people is safe during board and disembarking. The gangway almost become a necessary size eqiupment same as marine loading arm at oil dock.  
The gangway must have good technical performance for the environment through its function is simple. For adapting to the fluctuation of ship to dock and the happenchance, a detail analysis about information of hydroaraphy, weather and ship which shall arrive of the port will be carried out during design, to confirm the suitable operation condition and choose the correct schme and reliable preventive measure so as to attain anticipative purpose.
Gangway designed and manufactured by our company have many types for celection. Usually adoptting mechnical and hydraulic drive system for drive mechanism of gangway, and equipped various protection device as per requirement during design to ensure each drive mechanism safe operation, determine to adopt explosion proof electrical equipment for gangway according to the characteristic of handing oil at dock.
Technical characteristic:

1. The gangway designed and manufactured by our company combined the charateristics of the same of every manufacturer and overcame the shotage to make a convenient, agile, steady and safe operation and convenient maintenace.
2. the ladder body is of almuinium alloy and it is light and safe.
3. adopt four-link mechanism for steps, and steps will keep in horizontal when the ladder changing in a range of minus 45degrees to 60degrees.
4. the triangle ladder and front ladder are connected with single point, so that the land wheel under triangle will still keep contacting with deck of ship steadily and be immune from influence from bump of ship and inequality.
5. the hydraulic system is arranged suitably, weatherproof and convenient to maintain.
6. loacking performance of the lifting mechanism is firm and interlocked.
7. the electric control system is designed independently by our company and adopt domestic and international products of famous manufacturer for main components, has reliable quality and good performance.
8. the wireless remote made operating more convenient.
9. the gangway designed and manufactured by our company completely meet following government standard:

ⅰ. “hoister design standards”
ⅱ. “steel structure design standards”
ⅲ. “chemical and petroleum enterprise design standards—fireproof electrics”
ⅳ. “handing oil dock fireproof design standars”
ⅴ. “measurement of dry film thickness”
ⅵ. “surface rust grade and scale removal grade of steel before painting”
ⅶ. “erection quality test criterion for harbor equipment ”
ⅷ. “hydraulic system general technical specification”
ⅸ. “steel and alloy chemical analysis”
ⅹ. “high grade wire rope”etc. in latest edition
　　Main technical data:

variety and application scope of gangway ladder
（一）BL1 gangway ladder

（二） BL2gangway ladder
It is made of main ladder, front ladder, triangle ladder, slewing platform and riser. The gangway accomplishes pitching and horizontal slewing through hydraulic cylinder driving the mian ladder and front ladder. Main ladder cylinder and slewing cylinder can be in freewheel during contacting without counterweight. It is applied for the dock of 50000 taons capacity.(see right figure)
（三）BL3gangway ladder
it is made of main ladder, front ladder,triangle, slewing platform, draughting mechanism and riser. The gangway accomplishes pitching through hydraulic cylinder driving all ladders. Slewing cylinder can be in freewheel during contacting without counterweight. It is applied for the dock of 80000tons capacity.(see right figure)
（四）BL4gangway ladder
It is made of main ladder, front ladder, slewing platfrom, lifting mechanism and tower frame. The gangway is equipped with multiplatform. The triangle ladder, front ladder and main ladder are arranged for an arm to make more application range, through hydraulic cylinder driving the ladder to accomplish pitching and extending. Entending and shrinking of slewing cylinder drive the platform slewing in a range of minus 90degrees to 90degrees in the horizontal. Accomplish elevating of the slewing platform by the reducer pulling platform and ladder through pulley block. Slewing mechanism and main ladder can be in freewheel during contacting. It is applied for the dock of 50000tons capacity.(see right figure)
（五）BL4Agangway ladder
It is made by bearer frame, accommodation ladder, steering post, lifting frame, tower frame, platform of tower frame, ladder, handrail, lifting mechanism, cable lifting device, circumrotating mechanism, counterweight of accommodation ladder and electro-hydraulic control system. The boarding ladder is equipped with multi-platform, and accommodation ladder is composed of main ladder and triangle ladder. Pitching of the accommodation ladder will be actualized by cylinder or draughting mechanism, the turning function of circumrotating mechanism is accomplished by the circumrotating platform pulled by single extension bar of oil cylinder. The platform’s rise and drop of circumrotating platform and accommodation ladder equipped with counterweight is drived by the reducer. In order to prevent the disorder array of the cable during the process of rising of dropping, the boarding ladder is designed with cable elevating. Slewing mechanism and accommodation ladder have the function of floating after the lap joint between the accommodation ladder and ship.
（六）embarking with hose crane
Guide for selecting gangway ladder
Selection of gangway ladder shall be carried out according to dock capacity , change of tide, condition of dock surface and cost performance. Customer should fill the following parameter list and submit it to the manufacture so as to confirm the envelop range, basal dimension and load information of gangway.