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There have been a few unforeseen problems with the spinning that has slowed things down a bit. There are now 13 strands on each side with only 24 to go one each side. We are looking at finishing at the end of Oct. There are about 45 ironworkers on the job now, maybe a few more. The spinning is done in two 9 hour shifts.
We have finished spinning strands 14,15 16, & 17. HALF WAY!! My crew's part of this is basically very boring work. I get
a list every morning of the strands that require work and which strands can be compacted and banded. We use a hand tool to compact the wires into a
circular shape and then put a stainless steel band on it to keep the shape. Then we move 3 meters down the strand and do it again. And so forth across the bridge.
This requires 3 to 6 ironworkers 10 hrs a day. But it is not near as boring as standing on the footbridge and waiting for the wheel to come by
every 5 minutes. This is the job of the spinning crew in mainspan and the sidespans. When the wheel goes by they guide the wires into the cable formers.
At the tower tops every wire has to be in it's spot in the groove. The crews up there have to be attentive to keep the wires straight.
Just a little note here about walking on the footbridge. When you walk down onto the footbridge from one of the towers, it is steep on the mainspan and steeper on the
sidespan. You have the choice of walking on the mesh (which of course you can see through) or walking on the wood slats. The wood is about 3x5
and spaced close enough to be comfortable to walk on, but it makes my feet sore. The mesh gives when you step on it, which takes some getting used to.
I prefer walking on the mesh for most of the way, but near the towers where it is so steep I have to walk on the boards. Because of the give in the
mesh and the wave effect of walking on suspended cables, just walking from tower to tower is a workout. There is little or no side movement, even
during heavy winds. I suspect this is because of the three cross bridges evenly spaced across the bridge.
We have finished spinning strands 18,19, 20 & 21 on both cables. I did the termination splices for the east side on Thursday. It was rather confusing at first as there are 8 wires dogged off (attached) to the footbridge about 100 ft from the north anchorage splay saddle. I guess a little on the splay saddle and anchorage and anchorage is in order here. The wires are attached to cast steel shoes that are attached to two large (2") rods that are embedded many feet(I don't know exactly how far) into the concrete of the anchorage. The concrete block that is the anchorage measures about 30 ft wide by 30 ft high by 60 ft deep. The rods go through sleeves in the concrete and are arraigned in a diamond pattern probably 15' by 15'. The main cables themselves will only be about 22 inches in diameter, so the saddle that receives the wire coming from the tower must open up at the back side to let the wire/stand splay out to the 15' by 15' diamond pattern. This is where the cable gets it's strength to hold up the bridge. The anchorage I have described is part of a chunk of concrete in the ground that must be 8' thick and 60' by 100'.
Completed Strands 22-25 on the east cable. I haven't told you about the towers yet... The towers are poured in place hollow concrete legs with only two struts. One strut (cross member) at road level (about 125') and one at the top. The east legs of both towers will hold a staircase and the west legs will have the elevators. I ran the gang putting in the stairs on T3 (the north tower). We were almost complete when the cable process started in June and we have not been back since. It will get done eventually.
CABLE SPINNING IS COMPLETE!!! We finished spinning last night and not a moment too soon for my taste. You may have noticed I have not posted any updates for a couple of weeks. Why?? Because there is nothing new to report. It's similar to working on a high rise building. After the heavy iron in the first few floors, it's the same thing to the top. Boring! Alas it is done and we can get on to something new.
That would be compacting the entire cable down to its final size of 500mm. (about 20") The machine used for this has six 200 ton hydraulic jacks aligned radially. Once the Cable Compactor is mounted on the cable, the jacks squeeze the cable down to the right diameter and a 1" stainless steel band is installed around the cable to keep the shape. I am not involved in the actual compacting, but my understanding is that as the jacks are released the compactor slides down the cable the specified distance. (I have no idea what the specified distance is) The process is then repeated until the whole cable is compacted. There are 4 compactor machines: one for each of the side spans and two for the main span.
Monday everyone will be working the 7:00 am shift till 1:00. The company will be putting on a Topping Out Party at the Crockett Bass Club where all the safety lunches are held. It is near to the Nantucket restaurant which serves excellent seafood. It would be nice if the Nantucket catered the party. Yea Right!!!!
I really need to introduce you to my crew. They are:
Halloween proved to be an eventful day for me. Myself and 3 other ironworkers started putting together a Manatowoc 4000 crawler. I was working with an apprentice, Limy Nick, picking the middle counterweight off the low boy truck with a 60 ton hydro when one of the chokers slipped and the block jerked over to one side. Unfortunately that is where I was standing. It knocked me 10 to 12 feet backward through the air before landing on a pile of rigging we had laid on the deck. I sustained a concussion and a couple of stitches in the back of my head. I actually have no memory of the accident. I was standing...I was on my back! First time I have been injured at work since 1989. Thanks to Nick, Dave Nathan, the crane operator, and an unnamed guy from the boat works next door for helping me in my hour of need. Of course I am OK. I was back at work the next day and just hope they don't notice the dent in the load block. d3~)
Now on with the job progress. Now that the spinning is done we are concentrating on compacting the main cable. My crew has been doing the seizing of the strands at the anchorages. This is done between the splay saddle and the anchoring shoe. After the splay saddle the strand starts to separate into four smaller strands to go around the shoe. At 6 meters from the shoe a forming frame is put around the strand and then the strand is hydraulically pressed down to the original strand shape. We then wrap 5mm galvanized wire around the strand for 300 mm to maintain the shape. The Norwegians have a very slick little hand machine for doing this in the tight confines we find ourselfs in. The rest of the crew is involved in preparations for the cable bands. Cable bands are cast steel saddles for the suspender cables. They are in two halves, top and bottom, held together with threaded rods. The 4000 will be setting the bands from the South Anchorage to the crossbridge on the south side span. The rest of the cable bands from T2 to the crossbridge will be set off of the tram car. The tram car can be seen in the picture above with Roger setting the tram beam. After all the spinning equipment is removed from the tram strands (also using the tram car), the tram car will ride down the strand with the cable bands hanging on chain falls and will be set by hand. A hydraulic tightener will be used to tighten the nuts on the threaded rods to bring them to torque.
ManPower Update: The layoffs have started and a few have been laid off. I will miss John Pendleton the most I think. John was on the 2:00 to 10:30 shift and would set up a fishing line while he was working on the spinning crew. This put John 150 feet above his line, so he couldn't see when he had a bite. The ever resourceful John installed a light and a switch on the line so it would light up when he got a bite. He could see the light even from 150 feet at night. But what if the fish worked his way free before John could get down to it? John atttached a piece of surgical tubing to the line so when the fish pulled away the rubber would snap him back and reset the hook. The Man is a genius!
