Field Engineering Commandments (The Field Engineering Non-Negotiables In Construction)

Field Engineering Commandments (The Non-Negotiables in Construction)

In this blog, I’m going to take you through the practices, and I’m just going to call them commandments, the things that you have to follow if you want to get your layout and control and your lift drawings and your building components right. Meaning, you want to build with quality. So let me tell you a story before I go back here to the board.

At Hensel Phelps, they have a rich history of field engineering, and they know how to do it right. Emeritus professor Wesley Crawford from Purdue University did a number of sabbaticals with Hensel Phelps, wrote Construction Surveying and Layout: A Field Engineering Methods Manual. And literally, Hensel Phelps to this day still does field engineer boot camps and has advanced training programs and follows these guidelines.

And I’m not blaming surveyors. I love surveyors. Although we do need everybody to step up in their understanding of field engineering, especially surveyors, because you can’t just go stake points and call it good. That’s not how it works.

The Pain of Not Following Field Engineering Commandments

What they started to do was try and talk a certain region of the company into just using surveyors. Hensel Phelps didn’t buy off on it. They’re smarter than that. But anytime those survey consultants came in, they were causing all kinds of problems. I mean, before it was caught, buildings that were laid out outside of the property line, elevations multiple inches off. I mean, big, big problems. And they’re like, “Hey, we can’t do this.”

So I worked at Hensel Phelps, and so this is a credit to them. They were like, “Hey, let’s push that influence out and get back to basics.” And I want you to know that this list of commandments, anywhere it’s tried, takes a group of performing field engineers or surveyors from making mistakes to being very good when it comes to quality because they’re double-checking their work and because they’re using the right practices.

And so I won’t say all mistakes are gone, but we all know that mistakes happen every now and then if we’re not doing the double-checks. But this literally will transform a business from failing when they’re doing their own layout, their own field engineering, or double-checking to massive success. So let me take you through these commandments. And they’re non-negotiable. Meaning, this isn’t Jason’s opinion. These are non-negotiable. If you don’t like me, at least love the information. If you follow these practices in your company, you will get this right.

Commandment One: Traverse Your Primary Control

Number one, traverse your primary control. If your building is in the middle of the site and your primary control is a set of points surrounding the building that’s permanent, that’s in concrete, that’s used to locate all structures, then you must traverse through these points. And I prefer the compass rule. You can use a least squares adjustment and you can take redundant shots, but compass rule is my preferred. And if you talk to surveyors, they’ll be like, “You’re crazy.” But you’ve got to understand that when you get down to the tolerances that we’re attempting to hit at the building, you have to do this. None of these are optional.

So you traverse the primary control with the total station using tribrachs, doing a distance shot, then a direct reverse, direct reverse, at a minimum distance shot point to point. Then mathematically you will close that traverse, and you want a good level of accuracy. You can find this in the book, in the Construction Surveying and Layout book, and you have different, basically, orders of accuracy. But I always wanted one in 50,000, meaning that it would take me 50,000 linear feet to be off a foot for that quality of survey work. I wanted above 50,000. I want it to close well. If you do that, you will have a good, solid base network of points for your primary.

Commandment Two: Tie to BOB (Basis of Bearings)

Commandment two, tie to BOB. I’m not talking about Monsters vs. Aliens, the kids’ movie. So BOB is basis of bearings. Meaning that hopefully two of the points are actual coordinate points, city monuments with city coordinates and a design benchmark on it, so that you’re tying your overall network to the actual basis of bearings from which the building was designed.

Commandment Three: Level Loop Your Primary Control

Number three, level loop your primary control. That means that in addition to your traverse, you will set up your automatic level and do a backsight, foresight. You’ll do automatic level, backsight, foresight, backsight, foresight, backsight, foresight, backsight, foresight, backsight, foresight, and close on that original point. And the benchmark that you got from the design benchmark is transferred through a closed level loop that meets the order of accuracy. All of those are adjusted, and the elevations are correct. I believe in version three, it’s page 716 that shows the formula to see if your level loop closed well enough. But you have to make sure you level loop your primary control to get your elevation.

Commandment Four: Go Through Two Benchmarks

Commandment number four, whenever you’re doing level loops, you need to make sure you go through two benchmarks, that you estimate on the rod to the nearest thousandth, and that you always close. If you don’t do this, you’ll be in trouble. If you do one benchmark and that benchmark is off, your whole level loop will be off. That’s why you check to two. If you do everything to the nearest hundredth, you will not close within the accuracy on page 716. And if you don’t close, you won’t know if any of your work is good.

Commandment Five: Use the Right Tool for Distance Measurements

Commandment number five. If you’re going to shoot distances, and let’s just say that it’s over 150 feet, you can make it 200 feet, you can make it 250. You could make any rule you want. Definitely past the limitations of your total station, you’re going to use GPS. But typically between 150 feet and 1,500 feet, if the total station can sight that far, I will use a total station for distance measurements. Anything over that, like 1,500 feet, I’m going to use GPS. Anything between 150 and 1,500, I’m going to use the total station. Anything up to 150 feet, I’m going to use a chain. And anything within 35 feet, preferably 30, I’m going to use a tape measure.

Now, some people are like, “Jason, I’m just going to lay out the whole building with GPS.” Well, you won’t be within tolerance. “I’m going to lay everything out with my total station.” You got 3/16 worth of air in there. You shouldn’t do that with everything. Your chain will measure accurate dimensions spot-on, especially if you make sure that it’s tensioned properly, no sag, and you adjust for temperature. And then your tape measure. There’s nothing better within 30 to 35 feet than a tape measure.

Here’s the breakdown for distance measurements:

• Over 1,500 feet: GPS – Beyond total station limitations, use GPS for long distances
• 150 to 1,500 feet: Total station – If the total station can sight that far, use it for distance measurements
• Up to 150 feet: Chain – Chains measure accurate dimensions spot-on if tensioned properly, no sag, and adjusted for temperature
• Within 30-35 feet: Tape measure – Nothing better than a tape measure for short distances

If your project needs superintendent coaching, project support, or leadership development, Elevate Construction can help your field teams stabilize, schedule, and flow.

Commandment Six: Always Double-Check Your Work

The sixth commandment is always double-check your work. And that’s going to be with a different person, different technology, different approach, or a gut check.

Commandment Seven: Label Everything Permanently

Commandment number seven, label permanent. I want everything labeled. I want these on concrete monuments. I want them to have beautiful stamped brass monuments with stamped labels. I want LAF labeled beautifully. I want your secondary control, which is typically a baseline around your building, labeled beautifully. I want your grid lines labeled beautifully. I want everything labeled to the nth degree. Nobody should have to guess.

Commandment Eight: Setting a New Benchmark (Go Through Two Known Benchmarks)

Number eight, when you have a benchmark and I want to bring a benchmark into that location, somebody could say, “Hey, I just want to go ahead and set up and backsight and shoot the elevation.” No, no, no, no, no, no. What you’ll do then is you’ll then set up, backsight, foresight. And then you’ll set up, backsight, foresight, close the loop. Anytime you set a new benchmark, you have to go through two known benchmarks, and you have to close. And remember, you have to estimate to the nearest thousandth. This will make sure that that benchmark that you set is properly done.

Commandment Nine: Setting Baselines Properly

One other thing that I want to talk to you about is when setting baselines, there is a way to do it. When you set this baseline right here, you will set up, backsight, and shoot the end points. And then you will set up over here, backsight, and shoot the end points. Then you will shoot direct and reverse shots with direct distance shots and reverse distance shots and take the average. So baselines should be done from the end points, and then everything in the middle should be point to point, direct and reverse.

Commandment Ten: Use the End of the Tape Properly (Never Burn a Foot)

Now, this is a long list. We’re almost there. Stay with me. Number ten, use the end of the tape properly. The end of the tape on a tape measure is supposed to move. It moves out of its own way. So the thickness of that metal, that is the amount that it moves. So if you butt the tape up, it’s at perfectly zero. If you hook it, it’s at zero. It’s not ill-manufactured. It’s exactly what it should be.

Never, ever, ever, ever burn a foot. Even if you’re like, “Jason, you’re wrong.” Never burn a foot. It’s very easy to get zero holding perfectly with the end of a tape. Never burn a foot. You will start chipping down walls by one foot and having columns one foot in the wrong location. No professional carpenter or surveyor or field engineer or builder ever burns a foot.

Commandment Eleven: Radial Staking (Always Solve to a Known Point)

When you do radial staking, if you’re like, “Hey, I want to set up on this point, backsight, and go radial stake this point,” always solve to a known point to make sure that you’re oriented properly and set up properly.

Commandment Twelve: Use Prism Poles Sparingly

We’re going fast now. Number twelve, this is going to blow your mind. Use prism poles sparingly. And I would say when you use them properly, if you have a total station, it’s automatically going to have an inherent instrumental error of 3/16. By the time you shoot to a prism pole at the top of a prism pole to the bottom, typically there’s 3/16 to 3/8 of an inch of error because of how the level bubble works. Then you’re probably going to have at least 1/16 of marking error. By the time you add all this up, you could be up to three-quarters of an inch off.

Shoot to mini prisms. Shoot directly online. Avoid 4 ft prism poles. In fact, when I see surveyors out there with 4 ft prism poles doing everything, I’m like, they do not know what they’re doing because that will never be within tolerance.

Commandment Thirteen: Always Calibrate Your Equipment

Thirteen, always calibrate your equipment. Actually, 50% of the time you’ll get tribrachs wrong from the shop. And about 15 to 20% of the time, you’ll have something wrong with your automatic level. Very rarely with your total station, but always calibrate your equipment. We find chains, tribrachs, auto levels that are out of adjustment, and it’s going to cause you trouble.

Commandment Fourteen: Always Plumb from the Ground Floor

This is going to blow your mind. If you have a building, and I’ll tell you a story, and this happened in San Diego. We told the field engineering team and showed them how to plumb from the ground floor. We had those really high-powered green lasers, and it would shoot all the way up through the top, and we said every time you do a new deck and you need control, shoot from the bottom. Shoot from the bottom. If you got another deck, shoot from the bottom.

They started going from floor to floor, and the deck started to drift. By the time they caught it and called me in for help, 2 and a half inches. It was crazy. You always go, even if you’re on this upper deck, you plumb all the way back down to the first floor. That’s a crucial commandment.

Commandment Fifteen: Report Mistakes Immediately

And then the last one, if you find mistakes or errors, you report those immediately. Mistakes never get better with time. They only get worse with time. And so, if you find a mistake, you tell somebody right away, and you fix it right away.

A Challenge for Field Engineers

These commandments are crucial. If you implement these in a field engineering program, you’re set. If you don’t, you’re going to have massive problems everywhere and layout problems everywhere.

Here’s what I want you to do this week. Print out these commandments. Post them in your FE bullpen. Review them with your team. Follow them. They’re non-negotiable. They will transform your business from failing to massive success. That’s the power of these commandments. As we say at Elevate, field engineering commandments: traverse primary control, tie to BOB, level loop, double-check work, label everything, never burn a foot. Non-negotiables.

On we go.

Frequently Asked Questions

Why must you traverse your primary control?

Because you need a good, solid base network of points for your primary. Traverse with total station using tribrachs, distance shot, direct reverse, close the traverse. I always wanted one in 50,000 accuracy.

Why go through two benchmarks when level looping?

Because if you do one benchmark and that benchmark is off, your whole level loop will be off. That’s why you check to two. And estimate on the rod to the nearest thousandth. And always close.

Why never burn a foot on a tape measure?

Because you will start chipping down walls by one foot and having columns one foot in the wrong location. The end of the tape is supposed to move. It’s at zero when butted or hooked. No professional ever burns a foot.

Why use prism poles sparingly?

Because by the time you add instrumental error (3/16), prism pole error (3/16 to 3/8), and marking error (1/16), you could be three-quarters of an inch off. Shoot to mini prisms. Avoid 4 ft prism poles.

Why always plumb from the ground floor?

Because going floor to floor causes drift. In San Diego, they went floor to floor and drifted 2.5 inches by the time they caught it. Always plumb all the way back down to the first floor.