Pre-Crane Prep Work - Removing Doors, Building Trusses and Cleaning the Containers
December 13, 2010 - With the plumbing in and the foundation curing, we turned our attention to getting the containers ready for placement. We had just 6 days to locate an 11th container, get it shipped up to our property, get all the units cleaned, prepped and build 6 trusses cut to a tolerance of less than 1/8". So the work covered in this blog entry took place over six days starting with the hiring of Adam Falcon as the lead Welder for the project. Adam was recommended by his brother Brian who is a principal at Silver Rock Productions and our anchor tenant. Adam has worked not only as a welder, but a welding inspector.
Our work began with Adam by reviewing the Sketch-up file in detail. Adam understands CAD drawings and immediately provided us some insights on how best to do some of the upcoming fab work. We would need to get a good quality Plasma Cutter and Welding machine. Our search on Craigslist did not yield anything worth checking out, so we had to bite the bullet and buy both units at the local Northern Tool Supply store (I hate buying retail). The salesman at Northern Tool recommended a Hobart plasma cutter - Model AirForce 250CI - 12 Amp unit. The welding unit was a Hobart Handler Model #210. The plasma cutter was a mistake.
We were attracted to the Hobart 250CI because the unit had an internal compressor and the price $750. Based on the specs on the box, it should do the job. It did not. When we got it home and tried it out on some scrap metal, Adam was quickly frustrated by its performance. With all of the cutting we had ahead of us, we needed a unit that could stand up to the tasks at hand. We returned it to Northern Tool, and purchased the 250CI's big brother, the 500I ($1300). The bigger unit would require a compressor (which we had), and when we tried it out - it cut through the container walls like butter.
It took us over a day to get all the equipment up and running properly. A PowerGen 6500 watt diesel generator gave us the juice we needed to work out in the parking lot, hundreds of feet from the nearest outlet. It also gave us the 220 power needed for both the plasma and welding units. There are a lot of moving parts in a project of this size, and missing one simple item (a connector for the air compressor), can bring the job to a screeching halt. I spent most of 2 days just running down parts and pieces, and in most cases bought extra when possible because Murphy has a way of showing up at the most inopportune times.
We set a date for the crane to come to our property on Tuesday December 21st. Our Construction Manager said..."don't schedule a big job like the crane work on a Monday"..., and he was right. We needed Monday to get all the details worked out. Tuesday would be like a military drill, and we needed to get all the equipment, systems and loose ends resolved.
Rob Stengel of Container-IT came through for us on the 11th unit. It was another Evergreen HC box, but it was not in great shape. The floors had several damaged areas, but we would have to make it work. Leroy Jackson of Jackson's Rollback Trucking delivered the box, and helped us move some of the boxes we had stored behind our building to the front so the crane could access them easily.
We hired John Taylor as a maintenance man for epic, and he quickly became Adam's assistant welder. John took care of most of the odd jobs on the prep work including removing the vinyl decals on the boxes. This is not as easy as it sounds. The letters are made from an industrial vinyl designed to withstand the rigors of the open seas for up to 10 years. We found they would come off quicker if we heated them gently with a propane torch. Two men (hopefully who are friends with each other) can remove the letters by having one preheat the vinyl and the other pull it from the side of the container. The person using the torch must work very close to the person pulling the vinyl because the boxes soak up much of the heat on a cool day (it is best to work in the sun if possible).
We then turned our attention to cleaning the insides of the containers. Years of dirt and grime were evident on the floors, walls and ceilings, so we power washed every inch of the insides of the boxes. We aired them out, and the "container smell" that was obvious when they were delivered was now gone. They looked great, but it took the better part of a day to get them clean (when you have 11 of anything, a 45 minute job, becomes an 8 hour job.
While John and I were taking care of the insides of the units, Adam was busy figuring out how to build the trusses needed to hold up the boxes on the second floor. A quick call to our Life Line - Alex Klein - AKA Renaissance Ronin - helped us to understand the importance of the vertical struts our engineer had added to the units. To build them, we would need 180 feet of 2" x 2" x 1/4" tubular steel to make the six struts required. We would also need 6" x 6" plates for the base and top of each unit. Adam thought the addition of 8" triangular gussets would further increase the strength of these framing members.
We placed our order with Triple S Steel in Houston and headed down to pick up all the components we would need for the job. The Triple S yard is gigantic, comprised of several buildings with all the components you need to (literally) build a skyscraper. 2" tubing is available in 20 and 24 foot lengths, so 20 footers would result in the smallest amount of scrap. For pickup orders, they will make one cut for free and it just so happens we could get this done with their big metal cutting saw. The steel weighed just under a ton, and driving it back to The Woodlands (25 miles away) in a 3/4 ton truck was a slow trip to say the least.
I'll now describe the trusses, but please understand I am not an engineer, so do not do any of your structural work based on what we did for our job. Each building is different, and I would strongly recommend you get a licensed engineer for this part of the job.
The purpose of these trusses are to hold the weight of the container above it. Since the containers were not sitting directly on top of each other, we did not have the corner strength of the box on the lower level to support the weight of the box above it. Also, the corners of a shipping container are about an inch higher than the upper rails, so just stacking the box on the upper unit would not make it level. Our design called for 3 internal and 3 external trusses. We decided to do the internal trusses first. John used a 14" chop saw to cut the tubing to size. Adam cut holes in the roof and bottom rails to accommodate the tubing.
The 2" tubes were placed through the holes in the top and bottom of the container. The 6" foot plates were placed under the tubes and welded in place. A cross member was cut to span between both of the 2" columns and tack welded in place inside the container. The gussets were added, measurements checked, then everything welded in place. The plates above each of the tubes were then added, and the truss was complete. We got one internal truss built the first day, two internal trusses built the second day, and all three external trusses build the third day.
The next two jobs we tackled were to get the holes cut in the floors for the plumbing pipe stubs, and the removal of a set of doors that would be easier to take out prior to stacking. To cut through the floors we used a Sawsall for the 1-1/2" thick wood floors, and the plasma cutter to cut through the metal cross members.
For cutting off the doors, we tried using the plasma cutter, but had much better luck with the Sawsall. The salesperson at the Home Depot recommended we use a "Torch" Sawsall blade ($12), but we found the Vermont Tool blades (10 for $12) to be better. NOTE: These doors are VERY heavy and you must take great care when removing them so they do not fall and hurt someone.
I am writing this blog entry late on Monday afternoon. We had a "dress rehearsal" with our project manager and I feel we are as prepared as possible for the big day tomorrow. Jackson Rollback Trucking will arrive at 7:30am tomorrow, followed by the crane at 8:00am. Our goal is to get the job done (safely) in 6 hours. We have our work cut out for us.
Category: Container Building,