Palmer's Jarrow Shipyard: Cableway
NB This is a subsection of Palmer's Shipbuilding and Iron Co
Brief Description
A distinctive feature of the yard was the system of hoists running on cableways between large gantries. The leaning gantries are connected by a pair of tensioned cables and by the cables which support the three travelling hoists. Tensioned vertical guy ropes are provided outboard of the gantries. The three cables carrying the hoists are attached at each end to a powered carriage to provide lateral movement.
An additional, larger gantry was soon added, having four travelling hoists.
Contemporary Accounts
1905
'The new transporter crane at Messrs. Palmer’s shipyard is now fairly in working order. It is worked by electricity. The “cage” travels along substantial pulleys at height of 135 feet above the ground. Above this again are the wires which convey the electric current. Already it has shown the great amount of work which can be done. Under the old system I understand it took a couple of days to lay the keel of a vessel like the Lord Nelson, whereas it was laid last week in ninety minutes. Perhaps had the new apparatus been in use for a few months the keel might have been laid in even less time. The sensation up in the crane resembles that of being at sea. Of course the man in the cage is exposed to the elements, and just at present with a cold north east wind that savours more of winter than the approach of summer, the position is not one to be altogether envied.' [1]
1906 'I am told that 400 men will be displaced by the new overhead crane at Messrs Palmer’s shipyard. In future the plater will only require the services of say two labourers where it used to be more. It will be hard upon the labourers.' [2]
1906 Brief description of the system, designed and patented by John M. Henderson and Co of Aberdeen, at the suggestion of James Lindsay Twaddell, Palmer's shipyard manager, and his staff. The electric motors were supplied by the Lancashire Dynamo and Motor Co, with current supplied by Westinghouse generators driven by engines removed from torpedo craft.[3]
1906 From Engineering 1906/04/13: 'THE OVERHEAD WIRE CABLEWAY
APPLIED TO SHIPBUILDING by J. L. TWADDELL.
At the spring meetings of this Institution, on March 21,
1902, a paper entitled “Methods of Handling Material
over Shipbuilding Berths in American Shipyards,” by Mr.
Wm. A. Fairburn, was read. ...
'Described briefly, the system consists of three cableways suspended lengthwise over the building berth, carried at either end on specially designed cross-girders, placed transversely, one at either end of the berth, each supported at about 100 ft. from the ground by two inclined lattice-work steel columns; each of these girders is constructed in two parts with a clear space between, with rails on each half, on which travel the end carriages to which the cables are attached, the space between them admitting of the passage of the cables for transverse movement.
'The relation of the building berths to the river at the Jarrow yard, which is common to most yards in this country, almost precludes the adoption of vertical supports at the river end of a cableway, on account of the impossibility of obtaining guys of sufficient span riverwards. At the upper, or fore, end of the berths wire guys for staying vertical supporting columns were equally impossible, as, to be of any use, they would have to go well into the town. It was these difficulties which led to the adoption of inclined supports.
'In describing the equipment in more detail, it may be here stated that one of its advantages is the very small ground area occupied, each of the four concrete foundations for columns measuring 16 ft. by 16 ft. at ground level, .although the weight of concrete in each runs into 140 tons.
'From the heads of each of the four supporting columns are two adjustable back guys of steel wire, 6½ in. in circumference, dropping vertically, and secured through stretching screws into an anchorage of solid concrete. These, however, do not occupy much space, only presenting the obstruction due to two vertical wires in the case of the upper ones, and in the case of those at the river end, no obstruction at all, being so well out on the foreshore. A specially constructed seat built of mild steel is securely bolted to each concrete foundation to receive the heel of the supporting column, which is held in position by a steel bolt 8 in. in diameter. It will thus be seen that the columns are pivoted at their base. The heads of each pair of columns are securely bolted to the transverse girder, the distance between the columns being 94 ft., so that, looking down the berth, the structure has the appearance of a huge portal. The details of the cross-girders are as shown in Figs. 3 to 6. They are constructed of steel plates and bars, forming two separate girders, united at the ends, and of dimensions and strength to enable them to resist the lateral strain in the fore-and-aft direction, due to weight of the trolleys with their loads, as well as the strain due to the weight and tension of cables themselves; and, in order that these girders (100 ft. long by 11 ft. in breadth) may keep their form horizontally, vertical bow stiffening is provided, two bows being braced together on the upper side of the upper half of the girder and the lower side of the lower half respectively. A clear space of 4 ft. is provided between the two portions of the girder, to admit of the trolley cable, which passes through this space, being moved transversely ....
'... The transverse movement is obtained by either end of each main cable being attached to a carriage which travels on rails on the fore part of the forward girder and the after part of the after girder respectively. These end carriages (see Figs. 7 and 8, page 504), six in number, are strongly built, of steel, with a wooden awning, supported on a framework, and are traversed by a 12 brake-horse-power ventilated enclosed reversible motor, geared through worm and spur-gearing to two axles carrying cables and the weight of load-carriages, practically poises the rail-wheels. The motor on both end carriages is controlled simultaneously in either direction — i.e. to port or starboard — by the operator from the load carriage.
'The fore-and-aft trolleys, or load-carriages, are, as shown in Figs. 9 and 10 on page 504, and Fig. 11 on this page, constructed of steel, with a suitable cage for accommodating the operator, and a wooden awning carried on wrought-iron stanchions. Each of these carriages contains a 35 brake-horse-power enclosed ventilated reversible motor, which provides the power for hoisting and travelling motions, current being conveyed to the motor from overhead electric copper cables suspended between the supports, suitable collecting-arms and connections being attached to each load-carriage for the purpose of contact.
'The longitudinal travelling motion is obtained through friction and spur-gearing from the motor to the travelling motion shaft, on which two travelling-rope drums are keyed, one at each end. Two wire travelling ropes are stretched from end to end of each cableway, each being wound on its drum a sufficient number of times to prevent slip in the opposite direction to that in which the carriage is moving. Mechanical friction brakes are fitted to both longitudinal travelling and lowering motions, the operating levers and handles being conveniently arranged in the cage.
'The hoisting motion is conveyed through friction and spur-gearing to a drum running loose on a hollow-steel shaft, the load being lifted through four parts of wire rope and hoisting-block, the purchase being doubled by the block.
'Two suitable controllers, with resistances, are fitted on each load-carriage, one for starting, regulating the speed of, stopping, and reversing the motor on the load-carriage, the other for similarly controlling the motors on each end carriage, the current being taken from the overhead cables through the controller to a second series of cables connected at each end with the motors. The two end carriages of each cableway are thus operated simultaneously. The overhead copper cables for conveying current are attached at either end to steel spiral springs in compression, and a special arrangement of automatic cut-outs is attached to each of the three live wires, so that in the event of breakage the current is instantly cut off. The motors are all of the enclosed type, designed to suit the generating plant of the yard, which is three-phase alternating current, voltage 440, with a periodicity of 30 per second. All the motions of each cableway, including the simultaneous transverse travel of its two end carriages, are under the control of the operator from his position in the load-carriage, so that he has the advantage of being always over the load, and therefore can keep in touch with those on the ground or on the ship by signal, and has an uninterrupted view of the load and the position in which he has to deposit it. .
'The designed speeds aimed at were, for longitudinal travel, 600 ft. per minute; hoisting 3 tons at 100 feet per minute, or 1 ton at 150 ft. per minute; and transverse travel, 25 ft. per minute. In practice, about 400 ft. per minute for longitudinal travel is usually found to be sufficient, while the speeds stated for hoisting and transverse travel are usually maintained.
'The supporting columns, as already stated, are inclined, the angle at the river end being 55 deg., and at the fore end of berth 62 deg., from a level line. This inclination away from each other, with the weight of cross-girders and end carriages, against the weight and tension on the carrying cables and the weight of load-carriages, practically poises the whole installation in equilibrium, so that very little strain is thrown upon the end guys.
'The importance attached to the cables themselves in such an outfit makes it imperative that great consideration should be given to these. Each of the main cables is constructed of steel, with a tensile breaking strain of 75 to 80 tons per square inch, and is 7 3/4 in. in circumference, composed of six strands of 19 wires to the strand, the calculated breaking strain of each cable being 175 tons,
'In addition to the main cables, two horizontal stays of steel wire-rope, 5½ in. in circumference, are fitted, one on each side of the berth between the heads of the supporting columns, these stays being given the same sag as the main cables; in addition to which there are the two travelling ropes, 1½ in. in circumference, to each cableway. The calculations for strength were made to allow for a factor of safety of 5 on the main cable, and of 6 on the running ropes. The total quantity of steel material used in the end structures is about 278 tons, which is very much less than would have been required for any other system of over-head equipment.
'Having described the cableways as applied to the Jarrow yard, the writer may be allowed to make a few general remarks as to their working and upkeep. ....
'As to the general utility of the system, experience has proved its excellence; indeed, some features, which before the first gear was put into operation gave some anxiety, have since been found of benefit. For instance, it was thought that a load suspended on a wire of 500 ft. in length would have a tendency to surge vertically, and might make it difficult to place plates in the exact position required. In actual practice this fear was soon dispelled ; as a matter of fact, it is found to be a distinct advantage to have the plate or piece of material, while being lowered into position, suspended in a more or less elastic fashion, as is the case in a cableway. Take, for instance, a shell-plate ; it is only necessary to bring the plate to within an inch or two of its position, and the end of a spanner passed through a hole in the plate and the corresponding hole in the frame pinches it into place; whereas in the case of a rigid crane the plate would have to be manoeuvred into its exact position by the crane-man. Another point which gave some concern before the gear was operated was whether, when a load was suspended, say, towards one end of a cableway, and it was found necessary to move it transversely, the two end-carriages would move in unison. This, after adjustment of the motor resistances in the end-carriages, has been quite satisfactory, trouble in this direction ever arising. ....'
'.... the Palmer Company are now completing the erection of a second similar — though much larger — installation, covering a rectangle of 700 ft. by 150 ft., or two building berths, to be served by four cableways. In this equipment some improvements are being made as compared with the first; for instance, the electric cables will be grouped around a steel-wire rope, from which they will be supported at intervals of 76 to 80 ft. ....'
1907 From Engineering 1907/09/13: 'CABLEWAYS USED ON SHIPBUILDING
BERTHS' by John M. Henderson.
In 1906, at the spring meeting of the Institution of
Naval Architects in London, a paper dealing with the
system of cableways about to be described was read by
Mr. J. L. Twaddell, of Palmer’s Shipbuilding and Iron
Company, Jarrow-on-Tyne. At that time the first installation, serving a berth on which the battleship Lord
Nelson was built, had been completed in the Jarrow yard.
Since then two larger berths in the same yard have been
equipped in a like manner by the author’s firm. .....
'The cross-girders of the larger installation are as shown in Figs. 5 to 8, page 379. For convenience in erection the end girders were, in the case of both gears, made in two parts - an upper and a lower; they are built of steel sections, plates and bars, and are of suitable strength to resist the strain due to the weight and tension of the four cables, and of that due to the weight of the load-carriages with their load. The upper and lower halves of the girders are securely bolted to the head of each pair of supports ; and to prevent them deflecting horizontally vertical bow stiffening is provided. There is a clear space between the upper and lower portions of the girder, to allow of the transverse movement and vertical play of the cables and attachments. The lower portion of the girder for No. 2 gear at the upper end of the berth weighs 58 tons. While the outward inclination of the pillars, with the weight of cross-girders and end carriages, go towards balancing the weight and tension on cables and the weight of load-carriages, the structures are firmly guyed at each corner to a solid concrete block. The four steel-rope guys drop vertically from the head of the column to which they are attached to the anchorage, suitable means for adjustment being provided in each. The anchorages at the river end are well out on the foreshore, and at the upper end are put below ground, leaving only the vertical wires as an obstruction. There are also two steel rope stays, one at each side, connecting the heads of the upper and lower pillars on the port and starboard sides of the berth ; so that, although practically in equilibrium, the structures of the cableways are secured by those stays and guys, so as to be free of any movement.
'Both ends of each main cable are attached to a carriage which travels on rails fixed on the outer side of the upper and lower girders. The end-carriages are as shown in Figs. 7 and 8, page 504, vol. lxxxi. [reproduced above]; they are made of a steel framing, and are carried on four rail wheels. The four wheels are driven by an enclosed reversible motor of 12 brake horse-power, geared through worm and spur gear to the two axles on which the wheels are keyed. The motor on both end-carriages of each cableway is controlled simultaneously by the operator on the load carriage from any point along the cable ; that is, the movement of the cableway to port or starboard is regulated by the attendant in the cage.
'The load-carriages or trolleys on the second gear are shown in Figs. 9 and 10, page 504, vol. lxxxi [reproduced above]. They are also of steel framing, with a suitable cage for accommodating the operator, and covered in with an awning carried wrought-iron stanchions. Each of the carriages carries a 35-brake-horse-power enclosed reversible motor, from which power for both the hoisting and travelling motions is derived. The longitudinal movement of the carriage is obtained through friction and spur-gearing from the electric motor to a travelling-motion shaft, on which two rope-drums are keyed, one at each end. Two wire ropes are stretched from end to end of each cableway, Special collecting gear and connections are provided on each of the ropes being wound on its drum a sufficient number of times to prevent slip in the opposite direction to that in which the carriage is travelling. The hoisting motion is obtained through friction and spur-gearing to a drum running loose on a hollow steel shaft. The load is lifted through four parts of wire rope and hoisting-block, the purchase being doubled by the block. Mechanical friction foot-brakes are fitted to both longitudinal travel and lowering motions, the operating levers being conveniently arranged in the cage.
'The speeds are:- Of longitudinal travel, about 500 ft. per minute ; hoisting 3 tons, 100 ft. per minute; and lighter loads at somewhat higher speeds. The speed of cross travelling is 25 ft. per minute or thereby.
'The gradient of the main cables, irrespective of sag, is the same as that of the ground. In a length of 700 ft. the sag is about 22 ft., and in cases like that at Jarrow, where all materials are brought to the end of the berth, the load descends by its own weight, after being hoisted to the required position over the structure of the vessel. The return journey of the carriage is made when it is light, thus minimising the power required. In such an outfit the importance of the main cables makes it imperative that great consideration should be given to them. The wire of which they are composed was specially drawn, and has a tensile breaking strain of 75 to 80 tons per square inch, with an elongation of 20 per cent, in a length of 8 in.
'Special collecting gear and connections are provided on each load-carriage for the purpose of contact, and the chief point of difference between the first and second hoisting installations lies in the arrangement of the bare conductors for supplying energy to the load-carriage motor and control of the end carriages. On the first cableway they are arranged in a vertical plane, and six wires are used in two sets of three on each side of the load-carriage, these being stretched as tightly as possible between the two end carriages. The collectors on the load-carriage are of the sliding-contact type, and rigidly attached to each side of it. It was thought that this method could be improved upon, as there is a certain amount of trouble in keeping the sag of copper wires to correspond with that of the others. In the second installation the wires have accordingly been arranged in a horizontal plane, and their number reduced to five. There are, in addition, two supporting steel ropes at each side. The supporting cables are spaced apart by steel distance-pieces, into the upper side of which insulator bolts of tramway pattern bolts are fixed to carry the ears for holding the trolley-wires. The distance-pieces are spaced at 85-ft. centres, and give particularly rigid construction to the conducting wires, The arrangement is illustrated by Figs. 1 and 2, above. On the upper surface of the wires a bogie is placed, which is provided with wheels for running on the supporting cables, and also for making contact with the trolley-wires. Separate flexible cables are brought down from this bogie to the load-carriage, but the pull on the bogie is taken up by separate steel cable connections between it and the load-carriage. This arrangement, suggested by Messrs. Palmer’s and carried out by the author’s firm, has been found to answer admirably in all conditions of weather. The bogie and control wires can be reached from the roof of the load-carriage, a special platform being provided for this purpose. In the No. 2 cableway the wires are fed from a four-way distribution board on one of the bridges, four three-core flexible cables connecting the hoard with the trolley-wires. The distribution board is fitted with four three-phase overload circuit-breakers, one for each load cable, and the board itself is supplied with energy by a three-core cable leading up one of the legs. The reduction in the number of trolley-wires from six to five has been possible, because the reversing of the end-carriage motors is effected by reversing two of the phases, the remaining phase being supplied by a conductor common to all the motors. The motors are all of the enclosed type, designed to suit the generating plant of the yard, which is three phase alternating current, voltage 440, with a periodicity of 36 per second. ' With regard to the working and upkeep of cableways, no special expenditure has been necessary so far; certainly not more than would have been required fo outfit of jib-derricks. The main cables, as well as the running and hoisting wire-ropes, are kept saturated with oil; and in regard to wear and tear, it is estimated that the main cables, if kept in fairly constant use, will have a life of about six years. The cost of renewal per cable for the smaller gear would be about 95l, and for the larger gear about 150l. The steel structures were coated, after being built, with linseed oil, and painted at the time of erection. The cost of repainting both is estimated at 95l. to 100l.; and it is intended to do this about every second year. ....'
The article continues with discussions of costs and alternative material handling methods.
1907
'A JARROW MAN'S DREADFUL DEATH. At 10.20 this morning, a dreadful fatality occurred at the shipyard of the Palmer Company at Jarrow. An electrician's labourer, named Joseph Suddick, went to inspect some electric wires in connection with the overhead cranes. The travelling carriages are at an altitude of about 90 feet, and Suddick was in one of them when the accident happened. He fell to the ground, and was picked up dead. He alighted on his head, and was shockingly injured.
Deceased's terrible fall was witnessed by a number of men who were working in the vicinity, and the sad affair caused a painful sensation throughout the works. The body was conveyed to the mortuary of the Palmer Memorial Hospital. It is not known exactly how the fatality was caused. It is thought that Suddick may have come in contact with a live wire, and have been electrocuted before he fell from the carriage, or that while at his work he overbalanced himself and dropped to the ground.
The deceased was 21 years of age, and resided at 29, Henry Street, Jarrow. The overhead travelling gear, from which the man fell, was erected over the berth whereon the battleship Lord Nelson, launched in September last, was constructed, and traverses the entire length of the berth, the electrically propelled carriages on the cable ways in mid-air travelling from end to end. There are three cable ways having a span of about 500 feet, and Suddick dropped from the carriage on the western ways and near the incline supports at the southern end.
On each cable way there is a trolley carriage from which the hoisting and lowering are controlled by one man. The cranes are able to lift 3 tons 100 feet per minute, and all motions are electrically driven. A similar structure adjoins the one referred to, but is on a larger scale, and covers two berths 700 feet in length. This is the first accident in connection with the cranes, which have proved a successful experiment in facilitating the construction of vessels.' [4]
'SHOCKING FATALITY AT JARROW.
On Saturday afternoon, Mr Shepherd, Deputy Coroner, held an enquiry at the Police Station, High-street, Jarrow into the circumstances attending the death young man named Joseph Linn Suddick who was killed the previous day by falling from an overhead crane at Messrs Palmers.
Robert Suddick, brother, gave evidence of identification.
Albert Hudson, electric crane driver, said he saw the deceased lying across the live wires of the overhead crane. The body gradually slipped off and fell to the ground. The only place that deceased could fall off was the roof of the carriage. When deceased came up witness asked what he came for and was told he had come up to examine the wires. The top of the car was covered with rough canvas.
Henry Bloy, slinger, residing at 61, Queen's-road, said he was standing about about 20 feet from where Suddick fell. The deceased fell just below the carriage. He fell on the back of his head against the frame of a ship. The fall would be about ninety feet. The body was removed to the Memorial Hospital.
Joseph Parker, chargeman of the electrical department, said Suddick was a very cautious man. Witness asked him to go up on the cable to see if the trolley wire had got off the trolley wheel, and come back to witness and let him know, as he would send men up to put it right.
The Foreman asked if it would not be possible to have some protection but witness was of the opinion that it would be in the way.
Coroner said the evidence pointed to the fact that deceased was a capable man and had been going about his work a proper manner. It seemed to be purely an accident. The jury retired to consider their verdict and on returning the foreman said they found that deceased was accidentally killed but as to whether he was electrocuted or killed by the fall there was no evidence to show. The jury also recommended that in future when workmen were sent up on this kind of work the current should be turned off.' [5]
1938 The system was dismantled and the site cleared.