Special Boarding Ladder for Dock

Special Boarding Ladder for Dock

1. Special Boarding Ladder for Dock Application

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 strongly 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 boarding ladder almost become a necessary equipment same as marine loading arm at oil dock.
The boarding ladder must have good technical performance for the environment though its function is simple. For adapting to the fluctuation of ship to dock and the happenchance, a detail analysis about information of hydrography, 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 scheme and reliable preventive measure so as to attain anticipative purpose.
There are many types of boarding ladder for selection. Usually adapting mechanical and hydraulic drive system for drive mechanism of boarding ladder, 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 boarding ladder according to the characteristic of handing oil at dock.

2. Guide for selecting Special Boarding Ladder for Dock

Selection of boarding 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 manufacturer so as to confirm the envelop range, basal dimension and load information of boarding ladder.

(1) Terminal Parameters

NO.	description	data
1	distance between the centre of boarding ladder and the edge of dock	m
2	the standard elevation of dock	m
3	design the highest water level	m
4	design the lowest water level	m
5	nature thickness of protecting shipboard	m
	compressed thickness of protecting shipboard	m
6	voltage of power supply	V
7	frequency of power supply	HZ

(2) Vessel Data

NO.	description of data	data
1	minimum distance between vessel flange axis and deck	m
2	maximum distance between vessel flange axis and deck	m
3	the thickness of protecting shipboard	m
4	transverse drift(perpendicular to deck)	m
5	total fore and aft drift(parrel to the deck)	m
6	sinkage value of vessel	m

(3) Environment Data

description of data	item	data
maximum design wind velocity（10 meter upon the lowest water level, 3 seconds gust）	reset state	m/s
	movement/lap joint state	m/s
earthquake’s factors in reset state	probability coefficient of earthquake Z	G
	force acceleration of earthquake	degree
environment temperature	Highest	℃
	lowest	℃

3. Working picture of Special Boarding Ladder for Dock