Thames Barrier Project – Sep 1975 to Mar 1981 – Prepared by Mike Seward
As can be seen from the heading, I worked on the Thames Barrier project for an extended period of time and I had almost forgotten about it as a Sparrows project because my biggest time input was when I worked at Cleveland Bridge & Engineering, before I joined Sparrows. The good news is that I have found some photographs filed completely separately from my other work stuff and so I can give you a complete story, illustrated into the bargain.
I was working in Cleveland Bridge’s Darlington Head Office when we received the enquiry for the Gates and Machinery Contract for the Barrier. The other contract which was let was for the Civil Works, i.e. the foundations and piers and associated marine works and that went to a consortium formed by Costain, Tarmac and HBM (a Dutch company specialising in marine and harbour works). The consortium was named CTH. I was to undertake sub-contract work for that consortium later when I was working for Sparrows.
It was September 1975 when the enquiry documents arrived and I was immediately seconded onto the team which was to prepare the estimate. I provided full technical and programming support to the Company Chief Estimator and we worked closely together for 6 months until the tender was submitted. The challenges were immense, both in terms of methodology and time. There were many occasions when Peter and I worked right through the night and didn’t go home until the end of the following day.
The first challenge was to decide where we would fabricate the gates, and associated steel components, and how we would get them to site given their immense size and weight. Then of course there was the method of installation between the piers. When we had settled those questions, it became a matter of deciding how long everything would take and what would be the cost.
Peter and I had a very interesting visit to Rotterdam to see a very heavy lift involving four floating shear leg cranes, of 400 tonnes capacity each, working in combination. Neither of us had any experience of heavy lifting on that scale, or the precision with which it was carried out, but that visit did, at least, settle our minds on that particularly difficult stage of the work and we took a price from them. One of the above photos shows one of the large gates being lifted into position by two 800 tonne capacity cranes from the same company. Later, when we had secured the contract, a visit to Stockholm was necessary to finalise the technical details and price and programme for their input. Because of availability issues with the cranes, that commitment had to be made before the Civil Works had even been started on the site, i.e. years before the cranes were required.
The four large gates on the Barrier are 60 metres in span. And the weight is close to the combined capacity of these two floating shearleg cranes. See that they fit perfectly between the piers. The main lifting booms are only able to tilt forwards and backwards (that is where the term ‘shearleg’ comes from) and so sideways movement is achieved by manoeuvring the barges in the water – to tolerances of a millimetre.
We quickly decided to fabricate the gates on the banks of the River Tees, on purpose designed and constructed slipways. When they were complete, they were launched into the river (like ships) and towed down the North Sea and up the River Thames to the site. The construction of the slipways was a major project in itself and had to be timed and costed.
Next, the fabrication of the gates. Hollow steel boxes, curved on one side and flat on the other and comprising thousands of pieces of steel plate, welded together. We decided that a critical path programme had to be prepared and that became my task. The programme for a large gate comprised more than a million activities and each was given a duration in minutes and an exact allocation of manpower defined by skill. We were well used to building this type of critical path programme, but had never attempted anything remotely of this size. Each activity was linked to preceding activities which had to be completed before it could be started and likewise to following activities which it controlled. No computers, so this was a manually drawn diagram extending to several AO size drawings for one gate. Eight gates, plus gate arms to support them on the trunnions, 24 fabrications in total.
Using the logic, the earliest start date and latest finish date for each activity was then determined. This involved enormous amounts of manual arithmetic, but the outcome was a period of time within which each activity could be slid forwards or backwards without affecting the end date. Now, what did the graph of labour usage look like with all the activities adjusted to their optimum dates? We spent weeks trying to get the top of the labour graph flat for each discipline. This is called resource levelling and is essential in obtaining an economic and manageable usage of labour. We were running out of time and almost at the point of giving up when we heard about a computer in Manchester. A hurried visit. It occupied floor to ceiling cabinets in several rooms and was busy seven days a week. The only time we would be able to use it would be overnight for a strictly limited time. OK. But we had 24 programmes linked together by now and I can’t remember how many millions of activities. All our data had to be transferred to punch cards, with several needed for each activity. More hard work. A team of people was required and we finally got the data ready. Each night we used the computer. It took three hours to load the punch cards, before the start button was pressed. We then went away and came back in the morning to a mountain of printout. Only one problem, it was giving us nonsense. We looked for errors in the data input and of course found many, so we ran again. Still nonsense. After a couple of nightmare weeks, the software company who had written the programme were provided with our punch cards – across the Atlantic on an aeroplane – and determined that we just had too much data for the programme to handle. It was turning ones into zeros and vice versa. Now huge changes to the data to give a less detailed result, but nevertheless a sensible and usable one – just in time for incorporation into our calculations. In this advanced technological age, this work could be done in a fraction of the time using Primavera software on a PC!
This exercise dominated my life and the lives of my team for almost the whole of the tender period, and left us all exhausted. Our efforts were acknowledged by the Directors and we were all given time off to recover. The Consulting Engineers wasted no time assessing the tenders and we were called to London for a meeting. I went with my boss, John Fletcher, feeling sure he wanted me because my detailed knowledge of the Thames Barrier now exceeded that of anybody else in the Company. The meeting went on all day and at the end we were told that our tender had been successful. Immediately, John Fletcher introduced me as the Project Manager for the contract. I was gob smacked. He hadn’t given me any warning at all.
So you see, I didn’t just work on the Thames Barrier, I was in charge of it. On the train back to Darlington, John softened the shock for me somewhat when he explained it would be a temporary appointment. The Directors had decided that, if we were successful, the Company’s most senior Project Manager would be appointed. However, he was in Brazil finishing off the Rio Niterio Bridge and couldn’t be released from that until after completion. In the meantime, I was appointed as caretaker. It was six months before Denis Riley got back from Brazil and then it took a further period of months before he took over completely from me.
In the meantime, I finalized and completed negotiations for all our major supply sub-contracts, concentrating on those which had the longest delivery requirements. There were also many meetings with the Civil Contractor, CTH, in order to synchronise our respective programmes of work. They had many surprises, and delays, when they started to dig in the river bed and so the completion of the Barrier was delayed by several years. Meanwhile, the weather men were forecasting a really major tidal surge which would be sufficient to flood the whole of the centre of London.
I left Cleveland Bridge in early 1977 and joined Sparrows as Managing Director of Sparrows Contract Services. Within days, I had a phone call from the London Depot who had received an enquiry from CTH for some heavy lifting work at the Barrier. They had no clue how to deal with it. I sent one of my people up to London to collect the documents and they turned out to be concerning the installation of the Trunnion Support Structures. Meaningless to everybody except me. I knew exactly what they were because I had placed the sub-contract for their supply and, under the terms of the main contract, they were free-issued to CTH for installation in the concrete piers. How fortunate was that? So, what is a Trunnion Support Structure? Explanation with the help of the picture below.
This is an actual model at the Barrier site which explains its construction and operation with a cross section of a Falling Sector Gate. The segment at the right side is a section through the gate itself. With it in this vertical position the particular span of the Barrier is closed. The gate is 60 metres long and is attached at each end to a gate arm and is supported by it. The gate arm is the complete circular disc at the back of the model and this is supported on a trunnion which projects from the face of the concrete pier, at its centre. The gate arm can rotate on the trunnion which is like a gigantic bearing. The trunnion is made by forging, to give it the necessary strength to support the immense weight of the gate arm and gate. It is the largest forging ever made in the UK, weighing in at 85 tonnes. The forging is then machined to a conical shape and is the heaviest piece of metal ever machined to the dimensional tolerances required. Only one machine with the capability to machine such a large object to such fine tolerances existed in the UK at the time. I went to see it and it was the size of two semi-detached houses. I was responsible for placing the sub-contract for the manufacture of all the bearings – trunnions – in the Barrier (16 in all). The trunnion is supported by the trunnion support structure, no surprise given its name. This is an extremely complicated steel fabrication which is cast into the concrete pier in exactly the correct position (unbelievable tolerances). It is hollow and spans from one side of the pier to the other. A trunnion is attached to each end of the structure and these are held in place by bolts which span from one trunnion to the other and are very highly tensioned. These bolts fill the space inside the trunnion support structure and are 3 inches in diameter. The tensile loads are immense, like almost every other statistic of the Barrier. The Barrier is opened by rotating the gate arm and the gate until the gate resides inside the recess formed in the river bed by the concrete sill. That is the pale coloured structure at the bottom of the picture. It sits in an excavation at the bottom of the river. The top of the gate is then flush with the river bed when open to allow free passage of marine traffic.
The enquiry we received at Sparrows was for the installation of trunnion support structures in every pier of the Barrier. The largest of these on the 60 metre spans weighed almost 200 tonnes and were planned to be delivered adjacent to the pier by a barge. CTH had assumed that there would be a crane capable of lifting the 200 tonnes from the barge into the partly constructed pier, and that this crane could be supported on the temporary access scaffolding constructed by themselves at the side of each pier. Quite simply, the entire operation as planned was impossible.
We needed quite a bit of time to come up with a workable solution and this was quite unique and a complete surprise to everybody. In the picture's above you see our purpose designed gantry crane, twin beams spanning between two walkways on either side of the pier, and cantilevering over the river where the trunnion support structure would be delivered by barge. A lifting gantry travels on top from end to end. The magic part was that this gantry came in sections to the site, small enough to be lifted into place by a small crane and had the capacity to lift the required 200 tonnes. After each use, the gantry was dismantled and stored on a barge close to the site until it was needed again. We charged the full cost of fabrication of the gantry to CTH and at the end they were so pleased with the service we gave them that they donated it to us. We were subsequently able to re-use it in modified form for several other projects. A healthy profit was made and we had a very satisfied client.
CTH were so pleased with the service they had from us that they approached us to help with the installation of the sills in the bed of the river in each of the 60 metre spans. See the photograph of the barrier model above. Each sill weighed 10,000 tonnes and was constructed in a dry dock close to the Barrier. The dry dock was then flooded and the sill was floated out into the river and moored just downstream of the span which it would occupy. At this point, we took over, and again with specially designed and manufactured winches brought the sill between the piers. Six winches required for very precise control of each sill. Each winch had very special controls which allowed it to haul or pay out rope at a pre-set constant speed, or to hold the rope at a constant tension whenever required. This was cutting edge technology at the time. The tolerance to bring the sill between the piers was just a few millimetres. Once in position the sill was flooded and slowly lowered to the river bed on a hydraulic jacking system. This lowering method was undertaken by another Company, well known to us and with whom we had worked closely before. Our task with the winches was to hold the sill in exactly the same horizontal position as it was being lowered, so that it landed exactly on its bearings. Similar tolerances as before. The whole operation had to be completed on a rising tide and so was subject to exact time limits.
In one of the photos above the piers for three of the spans are at an advanced stage of completion and in the centre span of these three the sill can be seen partially submerged. Just visible on each end of the two piers are the Sparrows winches, painted red of course. Another prestigious project completed by Sparrows Contract Services to the exact and demanding requirements of the client and without incident.
Bontang – The Project – Oct 1980 to Feb 1981 Prepared by Mike Seward
Sparrows purchased the 1,000 tonne rated capacity truck crane for delivery in 1980. The Gottwald MK1000 was the largest mobile crane in the world at the time and was the dream of Leo Gottwald, the founder of the German crane maker. The Sparrow brothers granted him the realisation of his lifetime ambition when they ordered the crane, but unfortunately, he died before manufacture was completed. There were delays at the factory and so the crane could not be deployed to its first designated project at the Pembroke Refinery. Alternative provisions had to be made for that contract and they are detailed elsewhere in this section of the website.
However, an alternative commitment was quickly secured from engineers Fluor Daniel, for the lifting of 11 heavy vessels at their Bontang site on the island of Borneo in Indonesia. Photo No 1 shows the crane arriving at the site. There were, however, some fairly dramatic events leading up to that momentous arrival.
Of course, as is the case with all cranes, and particularly those with the greater lifting capacities, a rigorous testing programme is undertaken at the factory when manufacture is complete. This also provides an opportunity to rig and de-rig the crane for the first time and for the operators to gain essential experience. The Company’s two most experienced operators, David Stockman and Norman Small, who had both worked with the 500 tonne Gottwald crane since its purchase in 1972, spent 6 weeks at the factory in Dusseldorf. The drama came when the crane was completely rigged for the first time and the raising of the 103 metre main boom from the horizontal was commenced. This is the time when the absolute maximum compressive load is applied to the boom, and it proved to be too much for the design. The bottom section of the boom (the root) collapsed.
Immediately he got the news, Alf Sparrow, accompanied by Andrew Wyon, the Chief Engineer of Sparrows Contract Services, left on the Company aeroplane for Germany, where a meeting was held with the Gottwald engineers to establish the cause of the accident. Andrew had fairly recently joined the Company from Stothert & Pitt in Bath where he had been responsible for the design of their world leading range of offshore platform pedestal cranes. He was able to see that the German Engineers had omitted to include several key loading conditions into their stress calculations. However, it did take several hours of very intense discussion before they admitted their error. Alf sat through the meeting, of course understanding very little given the highly technical nature of it all. Andrew won the day and so the boom design was drastically modified. When Alf got back from Germany, he called me and quite simply said, ‘Make Andrew Wyon a Director’. There’s appreciation for you.
The second drama to be fitted in before the crane started its journey to Indonesia was of an entirely different kind. Out of the blue, we were approached by French heavy lifting specialist Montalev who wished to purchase a half share in the crane. It had cost £3.75 million, an extremely large sum of money at the time. So, they were very quickly given a warm welcome and their proposal for a joint venture company was considered and accepted without delay. Note that the name on the side of the crane in Photo No 1 is ‘Sparrows’. On the other side of the crane, the name is ‘Montalev’ so you can see why our photographs were always taken from the right side of the crane!
So, the crane was delivered down the River Rhine from Dusseldorf to Rotterdam where it was lifted onto what seemed to be a very small ship, given that the voyage to the other side of the globe would take six weeks. However, the size of the ship was dictated by shallow water at the site jetty in Bontang and there was no alternative. To give you an idea of scale, movement of the crane on the roads in Britain required 51 trucks as well as the carrier you see in Photo No 1. We were extremely worried, not least Alf Sparrow who decided that David Stockman should sail with the crane. Poor David was hard pressed to persuade Alf that even if anything serious were to happen to the ship, he would be powerless anyway.
Briefly, concerning the project, the crane really proved its worth in that it was able to stand in the middle of the site and erect all eleven vessels from one position. No other existing crane was able to do that and the savings in ground works were very substantial. Also interference with other site operations was absolutely minimal. In Photo No 2, the heaviest vessel weighing 750 tonnes is being lifted. The ship sailed around while waiting to bring the crane home. According to the captain, if he had moored at the site as was offered, he would have accumulated so much weed on the hull that he wouldn’t be able to move the ship.
Lifting the 750 tonne vessel at Bontang
Pembroke Project – Jun 1980 to Oct 1981 – Prepared by Mike Seward
The erection of 365 vessels and assorted items of heavy equipment for the Pembroke Refinery Expansion Project eventually proved to be the largest heavy lifting contract ever awarded in the UK. Sparrows Contract Services received the enquiry from Italian engineers Snamprogetti Ltd, and eventually submitted a successful bid in the face of stiff opposition from the rest of the heavy lifting industry.
There is an interesting story to tell. The enquiry document was unusual in that it included a bill of quantities which had to be priced per kilogramme of equipment erected. Different rates could be submitted per kilogramme, depending on the weight of the lifted item. It caused a great deal of consternation among my staff. They didn’t know how to handle this. I told them to cost the job as they usually would, arriving at a total lump sum for the whole of the work. This was done and I set about devising the kilogramme rates for the many ranges of weights. When multiplied up the bill of quantities had to amount to the total lump sum we wanted. It took me several days, but I eventually had a range of rates. A heavy vessel had the smallest rate and the smallest vessels had the highest rate, but sure enough, the whole added up to the lump sum. It turned out to be a master stroke. See later.
The usual excellent job was done on the technical submission and, most importantly, the Gottwald MK1000 crane was included to lift the heaviest vessel. We were sure it was the only available crane which would lift the vessel by itself and were confident that it gave us a very real edge over the competition. At this time, the crane had been ordered, but was not due for delivery for several months. Meetings were held with Snamprogetti, to the point where I was confident we were successful. When I was summoned to the next meeting, I called Alf Sparrow to tell him I thought this was the award meeting. ‘I will come with you,’ he said.
The morning was spent on the usual technical and commercial details, before the usual lunch at our expense. When we gathered after lunch, we were introduced to their Project Director who joined the meeting and who proceeded to express his concern about the availability of our 1,000 tonne crane, and what assurances we could give him that it would be delivered on time. I had conducted the whole of the morning meeting while Alf sat in attentive silence. Before I could think of anything to say, he put his hand into his inside pocket and pulled out a folded piece of paper which he handed to the Project Director. It was a personal letter to Alf from Leo Gottwald guaranteeing the availability of the crane. I was now completely speechless. I had known nothing about it. Deal done. The contract was formally awarded a few days later.
But this was not the end of the story. Only a further few days later, the Gottwald Sales Manager rang me and told me the crane was delayed. All hell broke loose, not least because he had spoken to me and not to one of the brothers. I don’t know exactly what was said, but I think some pretty strong language was used. Then I got a call from Gordon Sparrow. He wanted to know how much of the job could be done by the Demag TC4000 800 tonne crane which had just been purchased by J.D. White. I told him we had already looked into it and the Demag could lift everything except the very heaviest vessel. We could lift that with the Sparrowlift Masts. The next day, Gordon rang me back and told me we had purchased a Demag TC4000 which was almost due for delivery but had been cancelled. We had just spent £3.75m on the MK1000 and we were now spending another £1.5m in order not to let the customer down. I was in total denial. I just could not believe I was working for a company which would do such a thing.
Discussions followed with Snamprogetti when we assured them we would erect the largest vessel with our masts and there would be no additional cost, or delay. It was an amazing contract. At the peak, I counted 105 Sparrow cranes on the site (we had 350 in the fleet), not all working on our project, but we did have as many as 15 heavy cranes working for us. Our contract increased in value from £650K to £3.5m by the award of additional work, mostly in the small vessel range for which I had used the highest kilogramme rate. Remember? I think we made a profit of more than £1m. The Photo shows the Demag TC4000 lifting the Vacuum Column.
On different occasions, I flew Alf and George down to Haverford West in the Company aeroplane and then to site. Neither of them had seen so many Sparrow cranes in one place at the same time, and expressed the same reaction, that they almost believed we didn’t have that many. George actually broke into tears. The whole experience for me was just unique, and even life changing, witnessing that level of commitment to the customer. I will always remember my time at Sparrows as being one of ultimate enjoyment and fulfilment.
Arthur’s Table – The Project – About 1976 Prepared by Mike Seward
Photo No 1 shows a Sparrows crane with its jib apparently poking into the side of a building. A closer look reveals that it is poking through a window, so what is happening?
The building is Winchester Great Hall and on the other side of the gable wall is suspended a round table, said to be that of King Arthur. The challenge was to lower it down to the floor in order to carry out tests which would establish its true origin. Photo No 2 shows the table, which has been slung from the hook of the crane, seen outside in Photo No 1, and is just about to be lowered. It looks like Dave Evans, standing on the scaffold and Ken Cross is overseeing the lift from floor level. A special lifting frame was designed, which supported the table and prevented it from any damage during the lift.
The operation was successfully completed by Sparrows Contract Services Ltd, but the table was eventually found to be of a much later date than the reign of King Arthur.
Graythorpe Project – Oct 1978 to Dec 1978 – Prepared by Mike Seward
In the early Seventies, Laing Pipelines (Offshore) Ltd constructed an offshore platform fabrication yard at Graythorpe on Teesside. Two American Hoist & Derrick Revolver cranes of 800 tons lifting capacity, supported on 60 metre high gabbards, were utilised at the yard. Following closure, they were sold to a Greek client who was in an extreme hurry to take delivery. Sparrows were immediately approached to dismantle and load them out.
Another Job for Super Sparrow. With such a short programme in prospect, a completely fresh approach was required. A method utilising mast lifting equipment which had been purchased specifically for a recent project at Lindsey Refinery was quickly devised. We had sufficient equipment to build four masts of the required height, but the two cross beams, required to span completely over the Revolver crane were slightly short. A most ingenious solution to this problem was devised, which would eliminate the need to fabricate new beams. Laings were just desperate to proceed and gave their approval, although their engineers had extreme misgivings about our methods.
One crane was used to dismantle the other and that left us dismantling the second crane. First, the boom had to be removed, then the machinery house, weighing 400 tonnes, and finally the tub and slew ring weighing another 400 tonnes. Three lifts in all. We were on site only two weeks after the first phone call from Laings.
You see the arrangement of the Sparrowlift Masts in Photo No 1. In this Photo, the crane boom and machinery house have already been removed and the slew ring is being lifted off the gabbard. The cross beams, from which the load is suspended, climb up and down the masts utilising hydraulic jacking systems located just under their ends. This is a manual operation requiring the exact co-ordination of four individual operators. Also, the masts need to be exactly vertical before the cross beams are able to climb them.
Here lies the difficulty because the beams are shorter than the distance across the bottom of the gabbard. The masts are, therefore, leaning inwards, but the slew ring is only lifted a very short distance above the gabbard before lowering, and so the incline is not noticed by the masts. The gabbard is then travelled from under the masts. This is the most heart stopping operation of the whole process because the hydraulics which control its feet are at the end of their life and very difficult to control. So the gabbard does not travel in a straight line and threatens to crash into the bottom of the masts. Extreme danger! Once the gabbard is out of the way, the base of each mast is slid inwards, on a specially designed track, until it is perpendicular with the top. One base at a time with the 400 tonne load suspended near the top of the masts. Andrew and I did this ourselves, but the spectators all disappeared into the offices. No problems though.
The schedule for lowering the load to ground level was 13 hours because the hydraulics on the Sparrowlift masts are tediously slow. However, when lowering the first 400 tonne load, the jacks started to fail, basically because they had been designed for lifting under load and not for lowering under load. Eight jacks in all and, one by one, Andrew had to dismantle, modify, and re-assemble each jack while we waited for him. The lowering took 60 hours, and during that time, none of us left the site or slept. For the second lowering, which you see in Photo No 2, the jacks had been modified by a hydraulics specialist and so the same delay was not experienced. This was, however, an extremely stressful project, because of the pressure of time, and we were all glad to see the back of it
Dinorwic – The Project – Mar 1979 to Oct 1979 – Prepared by Mike Seward
Dinorwic Power Station is located 1,500 feet under a mountain in Snowdonia. Its turbines are driven by water from a lake at the top of the mountain, which then discharges into another lake at the bottom of the mountain. Of course, the upper lake has a limited supply of water, so electricity is only generated for short periods of peak demand during the day. It takes only seven seconds to start or stop the turbines. The enormous benefit is that two conventional power stations, which must run 24 hours a day, are then not required just to cover those peaks. The upper lake is then replenished by reversing the turbines to pump water back to the upper lake overnight. Surplus power from the grid is used. The build costs for Dinorwic were much higher than for a conventional build of similar capacity, but this was worthwhile because the savings in generation costs for the country paid for the station in eighteen months. What an amazing project, and the input from Sparrows Contract Services was key to its success.
The whole of the space for the station was tunnelled from solid rock in the heart of the mountain and the only evidence of its presence now is the entrance to the access tunnel on the bank of the lower lake. The construction of any power station requires the lifting of a great deal of very heavy plant and equipment into final position. Much of this is usually done by the permanent overhead cranes, but these have to be installed first. Engineers initially planned to lift these overhead cranes using rock anchors drilled into the roofs of the galleries, but when the rock was examined it was decided that it was too fissured to withstand the loads. Dilemma.
Super Sparrow to the rescue. Do you remember the weekly cartoon strip in the Construction News? When we were contacted by the CEGB, I sent Alan Gray to do the first visit with assurances that he would be able to solve any problem for them, no matter how difficult. Not surprisingly, they didn’t believe me. But of course, Alan very quickly grasped the enormity of the challenge and was able to leave the site having instilled complete confidence in the engineers that there was a way and they could just leave it to us. Super Sparrow had taken on the form of Alan Gray.
There followed a whole year of visits to the site while the engineering for the installation of each and every one of the overhead cranes was developed. Only then were we asked to tender for the actual work, in competition with others. We were not the cheapest tender, but had by then convinced the client that we were the only contractor with all of the necessary skills.
The photos illustrate the lifting of only one of the overhead cranes, but this particular lift was probably the most finely engineered I have ever witnessed. Two telescopic cranes were utilised, A Grove 130 tonne and a Demag 110 tonne. They were the two biggest telescopic cranes in the country at that time. The first challenge was to get them down the tunnels to the work site. Only just achieved with millimetres to spare on occasions. The first task was to lift the two bridge beams onto the gantry rails, and there was only just enough headroom available to do this. These were positioned well apart and a temporary trestle erected between them. See Photo No 1. Next, the very much heavier crane crab, destined to rest on top of the bridge beams, was tandem lifted onto the trestle. Levels were absolutely critical and were calculated to millimetres. Look at Photo No 2. The jib head of the lifting crane is almost touching the roof of the gallery. The crane hook has been removed, to save headroom, and the block is attached directly to a spreader and cradle which supports the crab from below, again to save headroom. With the point of support so low on the crab, great care was needed to ensure it didn’t just flip into an upside-down attitude and bring everything down. Once landed on the trestle, the crab was jacked up until it was high enough to allow the two bridge beams to be rolled underneath. Then the crab was jacked down again until its wheels engaged on the rails of the bridge beams. See Photo No 3. Job done? Not quite. The trestle then had to be dismantled and removed before both cranes could be derigged and removed. See Phot No 4. Only now was the overhead crane clear to traverse the full length of the gallery.
GCHQ Project – About 1981 – Prepared by Mike Seward
This is one of the many projects undertaken by Sparrows Contract Services, during my term of office, in which I had no involvement. It was just a matter of placing absolute trust in Alan Gray and Sam Tuckwell. The challenge was to transfer this listening dish from one track to the other track at right angles to it.
GCHQ thought we would have to use one of our very large cranes, but the ‘Dynamic Duo’ didn’t need more than a few moments to dismiss that ill thought out idea. They reverted to technology which they well understood from many years of experience. Namely ‘Ground Handling’. It now becomes apparent what is happening in the Photos. Masses of timber, jack the thing up and skid it. I remember them coming to me and asking me if it was OK to go back to the client with such a drastically different proposal, indeed one which may fill them with horror. My answer was in the affirmative and that was the last I heard of it. Job done. No scares, and a healthy profit made. More than that, a very satisfied client because they expected to pay very much more for what was, in their eyes, a very risky challenge.
Time and again, I saw my staff at Sparrows Contract Services reject the idea of lifting something, perhaps in order to relocate it, when they could move it by ground handling methods, which inevitably turned out to be cheaper and often less risky. A remarkable team who I felt extremely honoured to have working for me.
My later experiences, after leaving Sparrows, of undertaking many heavy lifts around the world, only served to confirm that I had indeed already worked with some of the very best people in the world.
Kenfig Viaduct Project – Sep 1976 to August 1977 – Prepared by Mike Seward
Erection of 160 precast concrete beams weighing 75 tonnes each using a specially designed travelling davit system. A production rate of 2.5 precast concrete beams per week meant that the use of conventional cranes for the erection of the spans was uneconomic. Either the cranes stood on site for extended periods of time, waiting for beams, or made frequent visits to site when sufficient beams were ready for erection. Both alternatives were extremely costly. For a much lower cost, the davit and beam system was designed, fabricated, and delivered to site. It then remained on site, at no cost, for the duration of the erection period. When the 16 beams, for each of the 10 spans, were ready, the workforce was mobilised to site and the davit system was deployed ready for lifting.
In the photograph, the first beam has just been lifted and the low loader, on which it was delivered, has been removed. The wire ropes, from which the beam is suspended, are pulled over the two davits by hydraulically operated bogies which travel on a special track, away from the davits towards the other side of the span. When the beam reaches full height, the davit booms are luffed in and the ends of the long red lifting beam are set down on the front toe of the davit bases. The lifting bogies are then disconnected and the davits are travelled backwards to the other side of the span, where the beam is placed in position on its bearings. Note the cantilever section of track, at the far side of the span, which supports the davits while they place the first beam.
Further developments of this highly successful Further developments of this highly successful equipment were subsequently designed and supplied to other projects, including one in Hong Kong.
Fawley – The Project – Sep 1980 to Oct 1980 – Prepared by Mike Seward
There is only one surviving photograph of this project, but it does tell the whole story of the lift. The Demag TC4000 600/800 tonne rated capacity crane, which is pictured, had only joined the Sparrows fleet earlier in the year and our customers were showing a great deal of interest in it. To the extent that we were awarded two contracts for it at nearly the same time. The first, was for Foster Wheeler Ltd, at the Fawley refinery of Esso and the second was for Davy McKee Ltd at the Grangemouth refinery of BP. There are no photographs of the Grangemouth project, but it did have some impact on the Fawley project due to their close proximity on the calendar.
As is always the case, dates are flexible and as they approached a deal of panic set in. There was going to be conflict. Who would win the toss of a coin? J.D. White had taken delivery of an identical crane at exactly the same time as us, so I elected to speak with Norman Hetherington of JDW. His crane was free and he was only too happy to do a deal with me, obviously worried about the prospect of his crane standing in the yard with no other likely customers. I came away from the negotiations well pleased with the profit I was expecting to make. However, I was concerned of the reaction of Alf Sparrow when I told him I was about to use the competition. I didn’t give Norman the OK till I had seen Alf. Alf said it would be a good idea if they painted the crane red but I did not precede with that.
Back to Fawley. The Photo shows the Demag rigged on tower and luffing jib and in position to lift off the old head from the Cat Cracker. This would be placed on the circular frame behind the crane position. The new head, already fabricated and in position, would be lifted onto the Cat Cracker. Looks easy, but the preparations and engineering input into these lifts probably exceeded any other I have ever experienced.
No space to rig the crane in its final lifting position and impossible to raise the boom and jib. So for rigging the crane was positioned in the open space just behind the three men who are standing next to the steel frame. The crane carrier was positioned in the same orientation, and exactly in line with its final lifting position. As each outrigger was attached to the crane carrier, it was fitted with a special steel wheel, which bore on a steel plate. The wheel on one outrigger can just be seen. The boom and luffing jib were then assembled to the crane along the access road to the right of the crane’s rigging position, and raised to their working elevation. The four steel plates under each outrigger wheel were then added to so that they made a track to the lifting position. Slowly, but surely, the entire finished crane was rolled along the track supported only by its special steel wheels. The eight rubber tyred axles of the crane carrier were not allowed to carry any weight at all. Once in position, the outrigger spreaders and mats were positioned and the crane was jacked up so that they supported its weight in working mode.
This was an absolutely unique manoeuvre, never attempted before, and one which caused a great deal of worry for all concerned. The planning went on for months before the lift and a scale model of the site and the crane was built in Foster Wheeler’s Reading office to prove all the details. During and after the move, crane outriggers and mats were actually positioned under existing plant (this is apparent in the Photo) and the model reproduced all of this detail. Of course, Demag engineers were very closely involved throughout to confirm the strength and stability of their crane. Needless to say, there was not a single problem with the work on site and the Sparrows employee who must take the most credit for that was Alan Morris who supervised the entire operation.
Westinghouse Project – About 1976 – Prepared by Mike Seward
This project is included as a perfect example of the type of work Sparrows Contract Services undertook every day of the week. The Westinghouse factory, just a little way down the road from us in Bristol was a regular customer. Just look at the limited space and headroom available for this topping-up. The foreman in charge is Ray Windless.