Widow-Makers

Aerial breaching in partially collapsed buildings presents a unique challenge

I’m not talking about the lessons of being prepared, keeping mindful of secondary devices, triaging of patients or working together—I’m talking about how we struggled in dealing for the first time with a partially collapsed building. In particular, I’m talking about how to remove or secure “widow-makers” (hanging concrete) so that others could look for survivors or recover the dead below us without becoming casualties themselves.

What to Do
There are many conflicting priorities to consider after the bombing of a building. These include the stabilizing the structure, securing the area, searching the building, dealing with the needs of the living and injured, and, eventually, the recovery of the dead.

Use the word “terrorism” or “crime scene,” and you may immediately create a conflict. Law enforcement agencies want to preserve the scene so they can catch the bad guys. Fire service rescue teams want to rescue the living by de-layering or taking the building or debris pile apart to look for survivors. Both have valid agendas, but if not approached in coordination, important evidence may be destroyed or vital rescue operations may be delayed at a time when seconds count.

The decisions made at unprecedented, devastating emergencies—like at the Murrah Building and, I suspect, in Mumbai—are by their nature complicated and controversial. It’s often a high-stakes game of roulette, with many decisions and options that have never been used or even considered before are presented to management.

For example, should hanging concrete floors and roof sections be cut and dropped? Blown up? Lifted up with helicopters or cranes? Or should they be secured to the building in place? Take the best structural engineers in the business and put them all in one place to have that discussion, and you may come away with more questions than answers.

The best advice may come from a discussion between a seasoned rescue manager, a crane rigger who has extensive demolition experience and a structural engineer who has had actual field experience. In advance of an incident, have those engineers and riggers spend some time around the firehouse dinner table building a relationship and developing trust.

What Happened
So what happened at the Murrah Building? Well, the night shift decided to cut down an 11,000-lb. slab of roofing concrete that was called “mother slab,” only to be stopped halfway through the operation by the day shift.

A specialist in building demolition assured the command staff that focused demolition using explosives could be safe and effective, but when you’re dealing with a building that has already been blown up once, it isn’t easy to convince folks that it’s a good idea to use explosives again and he was sent packing.

As for the helicopter, although sky hooks are great ways to lift and move loads, no one wanted to contend with the downdrafts associated with prop wash and the potentially negative affects they could have had on a very unstable structure as well as the work stoppages.

In the end, the task fell to us to both remove and secure widow-makers that weighed from 2000 lbs. to 6,000 lbs., each on the fifth, sixth and ninth floors. We approached in gravitational order, starting at the top and working downward. We employed all of our technical rope skills and equipment to secure personnel to the building, which becomes a significant challenge when building has been blown up. This gives a whole new meaning to “bomb-proof anchor.”

Add in a motorized Pomeroy core drill, a 40-lb. jackhammer, a sledgehammer, a cutting torch, a crane cable, a ram set and 2-x-4s—and you’re ready to roll. Tip: The guys who volunteer to be hanging on-line will need to understand that being in a full body harness for at least an hour at a crack—even a good one—will cause your legs to fall asleep.

The guys on the rope system is responsible for the main line, safety line and break systems must stay focused for extensive periods of time in an environment where it’s easy to become distracted.

The Routine
Lower the rescuer over the side with the ram-set, which should be tied off to the rescuer. Then lower or hand them the wood 2-x-4, which will need to be ram-set into the concrete as a kicker or sill for the rescuer to stand on, especially once the water to the core drill starts flowing. Lower the core drill, again, tied off, with at least a 5" drill-core bit, so that the crane-rigging cable can fit through it. Core the concrete in a spot or two that will allow it to be balanced well and secured when lifted by a crane.

Important: Try not to drop the cored section of concrete out of the drill bit, especially if you still have people working below you. They will get mad enough once you start flowing water to the core drill bit, but hitting them with concrete tends to not make you new friends. The bottom line: You shouldn’t have anyone working underneath you, but I’ve seen crazier things happen during chaotic events.

Once the hole or holes are drilled, run the rigging cable through the hole. Tip: I don’t recommend using crane soft-slings for this application. I’ve seen them fail if the slab moves around or equalizes once it’s put in tension or shifts during the lift. Hook the rigging cable to the crane hook and tension the cable. Punch out the joint or hinge with a small jack hammer or sledge hammer to create a minimum 4" gap or trench to expose the rebar. Use the cutting torch to cut the supporting reinforcing bars. I recommend a 4' or longer torch so the operator can stay far enough away from the edge in case something goes wrong.

Ensure the crane operator angles a swing away from the building once the final cut is made and that the swing isn’t so severe that when it starts coming back the other direction, it strikes the building, causing a new set of problems. The operator should be instructed to boom up and lower the load once it’s cut free.

If the decision is made to secure widow-makers in place, the same technique can be used to core the slab and then use metal cabling with come-alongs to secure it in place. Again, your biggest challenge will be finding anchor points to support thousands of pounds of concrete.

We secured slabs to the building in the blast zone at the Murrah Building. Working under floors with significant damage was somewhat unnerving as small pieces of the building tended to fall on us all day long. Pulling debris away from the edges of building floors open to the air should help. So should using plastic fencing to create an edge-safety perimeter on each floor, as well as a debris fence, especially if it’s windy.

One section of the fifth floor in the blast zone was so badly damaged that when we worked on it we had to construct a diaper from salvage covers below the slab before significant work could be done. Otherwise, we’d have bombarded the people working below us with concrete off the slab.

Conclusion
Aerial operations that consist of technical rope systems, breaching, breaking and cabling can be challenging but extremely significant to an incident in which a concrete structure has been damaged by an explosion, earthquake or other event. Removing those overhead hazards, or widow-makers, will greatly increase the safety of crews working below and open up new areas that shouldn’t be explored until the hazards have been abated.

Harold Schapelhouman is a 28-year veteran firefighter with the Menlo Park (Calif.) Fire Protection District. At the start of 2007, he became the first internally selected fire chief in 21 years for his organization. Previously, he was the division chief in charge of special operations, which includes all district specialized preparedness efforts, the local and state water rescue program, and the local, state and national Urban Search and Rescue Program (USAR).

Schapelhouman was the task force leader in charge of California Task Force 3, one of the eight California USAR teams and one of the 28 federal Department of Homeland Security (DHS/FEMA) teams.