As the bridge was now the major priority, Malchuskin and another Track guildsman and each of their gangs were drafted, about one half of the entire Militia force was relieved of other duties to assist, and several men from the Traction guild were to supervise the laying of the rail-way across the bridge. Ultimate responsibility for the design and structure of the bridge lay with the Bridge-Builders guild itself, and they requested fifty additional hired labourers from the Barter guild.
Collings and another Barter guildsman left the city at once, and headed for the local settlements; meanwhile, I was taken north to the site of the bridge, and was placed in the charge of the supervising guildsman, Bridges Lerouex, Victoria’s father.
When I saw the chasm I realized that the bridge presented a major engineering problem. It was wide — about sixty yards across at the point selected for the bridge — and the chasm walls were crumbly and broken. A fast-running stream lay at the bottom. In addition, the northern side of the chasm was some ten feet lower than the southern side, which meant that the track would have to be laid across a ramp for some distance after the chasm.
The Bridge-Builders guild had decided that the bridge must be suspended. There was insufficient time to build an arch or cantilever bridge, and the other favoured method — that of a timber scaffolding support in the chasm itself — was impracticable owing to the nature of the chasm.
Work started immediately on the building of four towers: two each to north and south of the chasm. These were apparently insubstantial affairs, built of tubular steel. During the construction one man fell from a tower and was killed. The work continued without delay. Shortly after this I was allowed to return to the city for one of my periods of leave and while I was there the city was winched forward. It was the first time I had been inside the city knowing that a winching operation was taking place, and I was interested to note that there was no discernable sensation of movement, although there was a slight increase in background noise, presumably from the winch motors.
It was during this leave too that Victoria told me she was pregnant; an announcement that caused her mother much joy. I was delighted, and for one of the few times in my life I drank too much wine and made a fool of myself. No one seemed to mind.
Back outside the city, I saw that the usual work on tracks and cables continued — if with a general shortage of labour — and that we were now only two miles from the site of the bridge. Speaking to one of the Traction guildsmen as I passed, I learnt that the city was only one and a half miles from optimum.
This information did not register until later, when I realized that the bridge itself must actually be to the north of optimum by about half a mile.
There followed a long period of delay. The bridge-building proceeded slowly. After the accident more stringent safety precautions were introduced, and there were recurring checks by Lerouex’s men on the strength of the structure. As we worked, we learnt that the track-laying operations at the city were going slowly; in one sense this suited us, as the bridge was a long way from being ready, but in another it was a cause for anxiety. Any time lost in the endless pursuit of the optimum was not good.
One day, word passed around the site that the bridge itself was at the point of optimum. This news caused me to look anew at our surroundings, but there seemed to be nothing unusual about optimum. Once again, I wondered what its special significance was, but as the days passed and the optimum moved on in its arcane way northwards it moved also from my thoughts.
With the resources of the city now being concentrated on the bridge, there was no chance of furthering my apprenticeship. Every ten days I was allowed my leave — as were all guildsmen on the site — but there was no thought now of my acquiring a general knowledge of the functions of the various guilds. The bridge was the priority.
Other work continued, though. A few yards to the south of the bridge a cable-stay emplacement was built, and the tracks were run up to it. In due course the city was winched along the tracks, and it stood silently near the chasm waiting for the completion of the bridge.
The most difficult and demanding aspect of the bridge-building came with running the chains across the chasm from the south towers to the north, then suspending the rail-way from them. Time was passing and Lerouex and the other guildsmen grew worried. I understood this was because as the optimum moved slowly northwards away from the bridge, the construction of the bridge itself would soon be laying itself open to the same problem that Malchuskin had shown me with the tracks to the south of the city: it was liable to buckle. Although the design of the bridge was intended to compensate for this to a certain extent, there was a definite limit to how long we could delay the crossing. Now work continued through the nights, lit by powerful arc-lamps powered from within the city. Leave was suspended, and a system of shifts devised.
As the slabs of the rail-way were laid, Maichuskin and the others put down tracks. Meanwhile, cable-stays were being erected on the northern side, just beyond the elaborate ramps that had been built.
The city was so close by, we were able to sleep in our quarters inside it, and I found a confusing difference between the extreme activity of the bridge site and the comparatively calm and normal atmosphere of everyday work inside the city. My behaviour evidently reflected this confusion, because for a while Victoria’s questions about the work outside were renewed.
Soon, though, the bridge was ready. There was a further delay of a day while Lerouex and the other Bridges guildsmen carried out a series of elaborate tests. Their expressions stayed concerned, even as they pronounced the bridge safe. During the hours of the night the city prepared for the winching.
As dawn was breaking, the Traction men signalled the clear… and with infinite stealth the city inched forward. I had taken a vantage point on one of the two suspension towers on the south side of the chasm, and as the city’s forward wheels moved slowly on to the tracks on the rail-way itself I felt a tremble of vibration through the tower as the chains took the strain. In the weak light of the rising sun I saw the suspension chains being tugged into a deeper curve by the weight, the rail-way itself clearly sagging with the immense burden being placed on it. I looked at the Bridges guildsman nearest to me, who was squatting on the tower a few yards away from me. His whole attention was on a load-meter, which was connected to the overhead chains. No one watching the delicate operation moved or spoke, as if the slightest interruption could disturb the balance. The city moved on, and soon the entire length of the bridge rail-way was bearing the weight of the city.
The silence was broken abruptly. With a loud cracking noise that echoed round the rocky walls of the chasm one of the winching cables snapped, and whiplashed back, slicing through a line of militiamen. A physical tremor ran through the structure of the bridge, and from deep inside the city I heard the rising whine of the suddenly free winch, sharply cut off as the Traction man controlling the differential drive phased it out. Now on only four cables, and moving visibly slower, the city continued on its way. On the northern side of the chasm, the broken cable lay snaked across the ground, curling over the bodies of five of the militiamen.
The most critical part of the crossing was done: the city moved between the two northern towers, and began to slide slowly down the ramps towards the cable-stays. Soon it stopped, but no one spoke. There was no sense of relief, no cry of celebration. On the far side of the chasm the bodies of the militiamen were being placed on stretchers, ready to be taken into the city. The city itself was safe for the moment, but there was much to be done. The bridge had caused an unavoidable delay, and now the city was four and a half miles behind optimum. The tracks had to be taken up, the broken cable repaired. The suspension towers and chains had to be dismantled, and saved for possible future use.