Goliath Crane

Goliath Crane

 

1.         The crane stood at 287 ft high

2.         It had a lifting capacity of 225 tons

3.         Built by Arrol & Co

4.         Goliath was built after the Geddes report recommended merging yards and concentrating on super tanker building

5.         The span is 350ft

6.         Goliath weighed 1500 tons

7.         The crane cost £750,000

8.         The crane was built in 1971

9.         A second smaller crane was planned but never built

10.        The crane driver's cab had a loo and their was a lift in the leg

 

The crane was half demolished on Sunday 3rd August 1994 It did not go completely to plan as the span of the crane did not break as expected with the impact

 

Following article taken from Scott Lithgow magazine of May 1972:

 

The size of the new Goliath crane is the first thing that strikes anyone visiting our new Glen Yard, or indeed visiting any part of Port Glasgow. It towers above the lower town, dwarfing even the high-rise flats and looking the upper town on the hillside straight in the eye. It is heavy, enormous, impressive. What is not so obvious is that it works with extraordinary precision.

 

The need for a crane of this kind arose three years ago when we decided to abandon our upper building limit of about 150,000 tons and equip ourselves to build ships of any size. It was clear from the beginning that methods which were efficient on the existing berths could not be extended to quarter-million-tonners and upwards. There were two main reasons for this. First, our biggest ships at that time were built by putting together prefabricated units weighing not more than 85 tons, and so many units of this size would be needed for the really big ships that fitting the jigsaw together on the berth would be impossibly complicated. Too many men would have to be concentrated on the spot. Too many pieces would have to be fitted together in awkward places. A crane with greater lifting power would allow bigger units to be built on the ground and so reduce the number of separate pieces to be assembled under difficult conditions on the building berth.

 

The other reason was that maximum throughput of steel depended to some extent on long production runs. Existing ships were built a slice at a time, cross-section by cross-section. the crane retreating up the berth as each was finished. The crane could never go back to an earlier section, because by then its rails were under the ship. This meant that the various parts that made up a section-bottoms, bilge units, side shells and so on had to be made together. But a crane which spanned the berth and was free to move up and down it at all times could lay the bottom for the entire ship, or all the bilge units, or whatever happened to suit the production plan, instead of chopping and changing from one to the other. Longer runs and greater flexibility in production would become possible.

 

The final choice has been a Goliath crane with a lift of 225 tons, spanning the new big-ship berth from side to side, with ample space not only for the ship itself but for large level areas beside it where the prefabricated units can be built up. It has been built by Sir William Arrol & Co. Ltd. and has just gone into service. Units of 80 to 90 tons come from the fabrication hall as before, but now they are assembled into much bigger units under the Goliath, to be lifted finally into place in one piece.

 

The crane looks simple, a very long girder with legs at each end; but some of the problems behind the apparently simple design become clear when one puts oneself in the shoes of the craneman. He sits in a little cab 240 feet above the ground driving a machine that spans 350 feet. It has two bogies running from end to end of the big main girder, one with two hooks and the other with one; and the whole contrivance, all 1,500 tons, runs up and down the berth on rails. The crane-is controlling three hooks in three ways, up-and down,, across and lengthways, and most of the time they are a very long way away. Even with radio contact via walkie-talkies with the slingers on the ground, how can he possibly judge precisely where the load is?

 

In fact he does not have to judge. He simply punches out the distance that the slinger on the ground tells him the load has to travel, and the crane measures it for him. The method is straightforward. He has beside him an assembly of push-buttons. If he is told, for example, to move the load 521 mm. across the berth, he pushes the button marked 5 in one column, the button marked 2 in the next column, and the button marked 1 in the third column. He presses a 'go' button, and up comes a neon lamp display with 521 on it. Then all he has to do is move the crane in the direction the slinger indicates. The neon display counts down the distance, and when it reaches zero he stops.

 

The count-down device works for any of the three operations, hoisting. cross traversing or long travelling.

 

The control system is based on the principle that as the crane can only do two things at once, only two control levers are needed. Which two things it does at any one time is decided by pushing buttons. There is a button for every movement (upper trolley, lower trolley, towards the river, towards the land, No. 1 hoist, No. 2 hoist, and so on) and a button for every possible combination of the three hoists (No. 1 hoist plus No. 2; No. 1 plus No. 2 plus No. 3, and so on). The driver just punches the buttons he wants, and does the rest with the two levers. One controls either long travel or the hoists, and the other controls the movement of the trolleys along the main girder.

 

But the crane's most elegant parlour-trick is its ability to turn a load right over in mid-air. This is difficult to describe, but not too difficult to follow if it is appreciated that one of the trolleys runs along the top of the girder on wide tracks and the other trolley runs along the underside on narrow tracks. The two trolleys can therefore pass each other without their cables becoming entangled. The hooks from one trolley are fixed to one end of the load, wide apart. The single hook from the other trolley is fixed to the opposite end, in the centre. The load is lifted. One trolley then lowers its end of the load while the other trolley raises its end; and at the same time the trolleys approach each other, pass, and move apart. The single hook is reconnected and the load is turned over.

 

The driver has radio contact with the ground, and a loud-hailer to contact people at a distance from the job in hand who may not have walkie-talkies. He also has instruments to tell him the wind speed and direction, the load on each hook, the total load on the crane and various other things, and there is a buzzer to warn him if the wind rises beyond a certain force. He has a comfortable heating system in his cab, and near it there is a lift to take him to his work, and a toilet. Safety systems stop the crane before it reaches its limits of lift or travel, and make it impossible when the crane is on the move for one set of legs to lag behind the other set on the far side of the berth.

 

There is no hint of any of this when the crane is seen at a distance, mainly because the eye refuses to take in the scale. It does not seem possible that there can be room for a lift inside one of the legs or for an emergency staircase in another. The transverse girder that straddles the berth and carries the trolleys looks massive, but it is difficult to appreciate that inside is a hollow space 40 feet high and running its full length that carries all the lifting gear and looks like the engineroom of a fair-sized ship.

 

The main girder weighs around 1,000 tons and had to be lifted into the air in one piece before there were any legs to support it. Arrols did the job by building two steel towers, each with two jacking beams working alternately. As the upper beam reached its limit the lower beam was pulled up under it and the move repeated. Months of this were necessary before the girder had been pushed up to the sky and balanced there with a tower supporting each end. Then the legs were hauled upright through pulleys at the tops of the towers, the heavier pair separately and the lighter pair already welded together.

 

The question now is what is to follow. The ultimate plan for the yard calls for a second Goliath crane able to pick up 800 ton block sections through the sliding roof of a fabrication hall alongside the building berth and place them straight into position on the berth; a Goliath so big that it will straddle the first one.

 

A second crane will be needed some day and it will certainly straddle the present one; but whether or not it will be able to lift 800 tons will depend on very careful study. There are two schools of thought about big cranes. One says build as heavy as possible, so that fewer pieces will have to be assembled on the building berth. The other says that three-dimensional 800 ton units are too big and inflexible, leading to fit-up problems on the building berth. Better, it says. to work with smaller, more flexible, two-dimensional units. This school would probably recommend about 300 tons for the Glen Yard's second crane.

 

When we have built our first quarter million tonner, we will have the experience to work out our sums in more detail. Meantime we keep an open mind and congratulate ourselves on the tremendous throughput of steel the new Goliath is already making possible.

 

It cost £750,000. Ordered today it would cost about double that.

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