Engineering Wonders of the World
Volume I

THE MARCONI TOWERS, POLDHU, CORNWALL. 443 and hauling them up to their fellow-workmen above. The workmen were all either Cornishmen from aloft. All descended safely except one, and the “ stool ” had just gone up to fetch him when the waterspout burst over the The Workmen. or men living in the district, and entirely unused to the class of work on which they were employed. Only eight out of the thirty- six aloft had ever been more than thirty feet ground. Those in charge of the hauling rope bolted for shelter, leaving the rope hanging. The man aloft, not seeing that the rope was deserted, stepped into the seat and let go, the result being that he came down the whole above ground ; yet but one out of the remain- distance of 2-15 feet practically without a ing twenty - eight found the great height too much for him, and re- fused to go aloft after seventy feet. In spite of the unusually cold and rough weather ex- perienced that spring, the four towers were ready to receive the aerials by May 1902, the whole of this portion of the work being accom- THE “ BO’SUN’S STOOL” AT WORK. check. Most for- tunately, the low- er ends of the stretched ropes were secured by several half- hitches, on to which the “ stool ” fell. These, acting as a spring, broke the force, and the man escaped with only a severe shak- ing which incapa- citated him for a few weeks. One could always see plished without a single accident sufficiently serious to stop any man working, though A Narrow Escape. work was in numerous were the narrow escapes from sundry articles falling from above while the progress. The only serious the heavy squalls to which this coast is sub- ject approaching from a distance across the sea, and a sharp lookout was kept for them. Work frequently had to be suspended for a quarter or half an hour, and the men aloft ordered to lie down flat to avoid being blown accident to be laid to the account of these off the scaffolding. towers occurred some time later while the The towers were designed on a basis of a finishing touches were being made at the top. In order to avoid the risks attending the use of ladders a primitive hoist was contrived. Two parallel hemp ropes were stretched at an angle to the tower from the top to the ground, and a short plank, technically known as a “ bo’sun’s stool,” was hauled up and down, using the stretched ropes as guides. One afternoon an extraordinary cloud bearing a waterspout was seen ap- proaching, and all hands were ordered down maximum wind pressure of 56 lbs. per square foot of surface, with a factor of safety of 5. It was estimated that such a , , j ! Extraordinary pressure would produce a total stiffness horizontal load of 50 tons on each tower. In addition to this, the strain on the horizontal ropes carrying the aerials was estimated at 9 tons when under the same wind pressure ; but through lack of precedent on which to base the last item, it would be difficult to say how near the estimates were