Analysis of container sway behaviour of rope and machinery trolley.
Report 2004.TL.6896, Transport Engineering and Logistics.
Since the beginning of the development of container cranes, two kind of
hoisting systems are used; the rope trolley and the machinery trolley.
Those hoisting systems are still in used, but the sway control of the
container in the crane becomes an increasing problem. That's why there is
in this report an analysis made of the sway behaviour of the container.
Based on the analysis the effectiveness of sway control between the rope
and machinery trolley is compared.
The machinery trolley has a heavy trolley with the main hoisting equipment
attached to it. The rope trolley has a light frame, which only carries the
main hoist sheaves. The hoisting device is placed in the machinery house
and thereby this system has much longer cables than the machinery trolley.
From the both systems are simplified models made in ADAMS. With these
models simulations are made of the both hoisting devices under different
circumstances. The following simulations are done; trolley driving, a
push, lowering the load, wind load, eccentric load and different sheave
The simulations results ended up in the conclusion that the model was
unstable. And in some cases the cable force became zero, which is hardly
possible. So there is chosen to simplify the model to get a stable model.
Looking at the results the deceleration of the trolley delivered a lot of
trouble. So to get the model stable the deceleration is forgotten. The
problem of the cable force that becomes zero can be avoid by decreasing
the acceleration to 0,6 m/s2 and change the cable length to 15
meter instead of 20 meter. This numbers are determined by tests with the model
and this where the maximum numbers at which the cable force didn't become
zero and the model looks stable. So with this simplification the
effectiveness of sway control of the both systems is compared.
With the new model the following simulations are done; trolley travelling,
trolley travelling, a push, wind influence, sheave displacement and
Still the simulation results were not reliable. The model that is used is
build up of components that are available in ADAMS. An expert has
delivered the program of the components, but it is clear that there is an
error in it.
In spite of this the conclusion is that the effectiveness of sway control
is better with the rope trolley. Because the rope configuration of the
rope trolley is stiffer and also the overshoot and the skewing of the
container were smaller with the rope trolley.
The recommendations are that the model must be improved. The best is that
the first model is improved to a good working model. By means of:
The following extensions are suggested:
- Improve the interaction between the ropes and the sheaves so the model
- Improve the trolley travelling in such a way that it moves as in the
There is a recommendation for the improvement of the stiffness of both
systems and that is to make the sheaves distance maximal. Because of the
guide system of the containers in the ship this is hardly possible. So a
hydraulic system is suggested, through which the distance of the sheaves
can be changed, when the container is above the guide system.
- The middle sheaves in the model of the machinery trolley ought to be
besides each other. (The drums lay beside each other in reality) This is
not the case in the model and can lead to big difference, because the
swaying depends for a great part on the rope configuration.
- Put the total rope system of the rope trolley in the model this gives
better similarity with the reality.
- A better look at the wind.
Reports on Transport Engineering and Logistics (in Dutch)
, TU Delft