Setting beams and columns on a Havasu site

Nothing Is Stable Until It Is Tied Together

A steel frame gets its strength from being complete. A single column standing on four anchor bolts is not a structure, it is a lever waiting for a reason. Two columns and a beam between them are better and still not braced against everything.

That is why the crane cannot set a piece and walk away. It holds each piece until enough connections are made that the piece will stand on its own, and that judgment is part of the sequence rather than a matter of feel.

The consequence for scheduling is that the crane is booked for the run, not for the picks. If there are ten pieces and each takes fifteen minutes of holding, that is the day, and it cannot be compressed by working faster on the crane end.

Anchor Bolts Are Where the Trouble Starts

The most common delay in setting columns has nothing to do with steel. It is anchor bolts that are not where the drawings say they are.

Bolts get set in wet concrete with a template, and templates shift. A pattern that is out by a quarter inch means a base plate that will not drop over the bolts. Now somebody is reaming holes, or the bolts are being bent, or the column is hanging on the hook while a decision gets made.

The fix is to check the bolt pattern before the crane comes. Take a base plate, or a template, or just a tape, and confirm every pattern on the pour. Ten minutes with a tape the day before is worth two hours of a crane holding a column while people look at each other.

The second thing to check is elevation. Base plates get shimmed or grouted to a set elevation, and if the concrete came in high, the column ends up high and every beam connection above it is fighting that error.

Fit-Up Is What Actually Sets the Pace

A beam flying into place has to land with its connection plates lined up with the holes in the column. That tolerance is small. Drift pins get driven to pull holes into line, and that works for a small misalignment.

When it does not work, you are looking at a shop error in the steel, a column that is out of plumb, or a bolt pattern that was wrong at the base and has propagated upward. All three take time to sort out and all three are happening with a beam hanging on a hook.

Good crews handle this smoothly because they check as they go. Plumb each column before it is signed off. Confirm elevations. Catch an error at the second piece rather than at the twelfth, because at the twelfth the error is baked into everything below it.

The crane is a party to this whether it wants to be or not. A load that is being held for adjustment is being held with the operator's hand on the controls, and that means the operator is watching that piece rather than doing anything else.

Where the Havasu Site Adds Its Own Problems

Caliche is the first one. It is hard, which is good for outrigger bearing, and it is inconsistent, which is not. A layer of caliche over softer material is a crust, and a crust is exactly what an outrigger pad punches through.

Grade is the second. Steel on hillside lots often means the crane cannot sit anywhere near where you would want, and the pick radius is longer than the drawing suggests. That is a planning item, and it sometimes changes the sequence, because you set the pieces you can reach first.

Heat is the third and it hits the crew harder than the machine. Steel in direct sun in July is untouchable without gloves, and a connection crew working on it slows down, which lengthens the hold time on every piece. That is a real reason summer steel work starts early.

Wind is the fourth. A long beam on a single hook wants to rotate, and gusts push a long member around a lot more than a compact one. Two tag lines at opposite ends is not optional on long steel.

Rigging a Long Member

A beam picked at a single point sags in the middle and hangs unstable. Two-point picking at the right locations along the span is standard, and a spreader keeps the sling legs from pulling inward and compressing the member.

Where those pick points sit matters. On a long span you want them positioned so the beam hangs level and the bending in the beam itself stays reasonable. On very long or slender members, the beam has to be picked in a way that does not bend it into a shape it will not fully recover from.

Orientation matters too. A beam has to arrive at the connection the right way around, which sounds obvious and gets missed. It is much easier to spin a piece on the ground than in the air, so we check the orientation before it leaves the deck.

Working With the Steel Crew

The relationship between the crane and the connection crew is the whole job. They are up there, we are down here, and the load moves according to one person's signals.

The things that make it go well are unglamorous. One signal person, agreed before the first pick. Radios that work and a hand signal fallback for when they do not. A clear rule that nobody is under a suspended load. And a sequence everybody has looked at, so the piece coming up next is the one they are expecting.

• Confirm every anchor bolt pattern before the crane is scheduled
• Check base plate elevations against the drawings
• Lay the steel out so pieces come up in sequence order
• Agree the signal person before the first pick
• Plan two tag lines on anything long
• Confirm the piece orientation on the ground
• Start early in the summer months

Staying on the Load Until the Connection Carries It

Some connections go together in a minute and some take a while. On the slow ones, having the crane hold the piece until the connection crew says it is made is a very different experience from cribbing it and coming back.

Holding a column plumb on the hook while the base is made up, or holding a beam in fit-up while the connection is completed, means the piece ends up in the position it is supposed to be in rather than the position gravity put it in.

The hook comes off when the crew says the connection is carrying the piece, not before. Letting go early to save a few minutes is how a column ends up out of plumb or a beam ends up on the deck.