Page 7 - Newsletter_November2017

Step 9: Step 10:

Notice the train going by. The That’s as far as the jacks will go…
railroad had flaggers on the tracks,
and train speed was reduced, but
the work continued below.

Step 11: Step 12:

Blocks added. In this photo they Breakthrough! Once the pipe
have about a foot to go, then they reached the sheet piles on the
remove the blocks and lower other side a torch was used to cut
another section of pipe. around the pipe and the jacking
was complete.

Step 13: Step 14:

Grout was pumped through three Conduit supports were required
ports in each pipe section to fill every 10-feet. The unistrut was
any voids outside the pipe. After put together on site and equipped
some touch-up painting the work with rollers so that no further
inside the pipe was complete. pipe entry was necessary.

Step 15: Step 16:

Electricians fastening conduits Once all the conduit was in, flow
to unistrut support. fill was pumped into the pipe to
fill all the voids and backfilling
of the pit and shoring removal
began.

Lesson Learned:
This operation was well-planned and went very smoothly. As the pipe jacking subcontractor was setting up, we noticed that the
blower to be used to provide fresh air to the pipe was within 5-10 feet of several pieces of gasoline/diesel powered equipment (a
generator, portable lighting plant, air compressor, and the power pack for the hydraulic jacks). We were worried that the exhaust
from the equipment might reach the fan intake and be forced into the pipe, and asked them to move the blower or the fuel-powered
equipment. They decided to move the blower approximately 20-feet away and started the operation uneventfully. At about the
midway point the wind picked up a little, and the tunnel worker in the pipe noticed an exhaust-type odor and the air monitor reading
low levels of carbon monoxide. The equipment up above was moved about another 20-feet from the pit and the issue was resolved.

Although it is unlikely that we will encounter much pipe jacking in our future, this example would be applicable to any confined
space entry work we do where a blower is used to force fresh air into the space. There have been countless examples over the years
where equipment was started or vehicles pulled up near the fan intake and dangerous conditions resulted inside the confined space.
It is important that the attendant for any confined space pay attention and protect the quality of the air being pumped into the space!