Installing Fabric Structures time lapse
Step #1. Installing fabric structures mounted on shipping containers
- When installing fabric structures the most important start is to mark out the site accurately so as you have the structure square. Plans give the corner to corner measurements. If you start off out of square then you will struggle to get the bolts and tabs to line up.
- Check all the components in the stillage and mark them off against the plans. This will ensure any new installers understand where the components fit. It also gives you time for rectification in the unlikely event of missing components.
- If you are installing piers make sure you have augers that can reach the depth you are required to go.
- Weld the brackets to take the “J” rod anchors to the containers
- Normally we will dig the piers then place the containers over the holes
- Chock the containers so they are level or for single height containers, leaning 5mm to outside to help water run off
- Fit the “J” Rods and pour the concrete
- Or is you are using ballast, fill the containers with dry ballast material using bobcats or a conveyor belt. The plans will tell you the weight of ballast needed. For smaller fabric structures a sheet of steel on the floor may give you the required ballast.
- Or if you are using external ballast in the form of concrete blocks, make sure they cannot move easily.
Spigots welded to the top of the containers
Step #2. Welding the base plates and frame spigots on containers
- Mark the centre lines for all the spigots to be welded to the containers. Beware not all shipping containers are the same length when it comes to the outside to outside measurements. Some of the older Russian containers fall into this category plus they also have steel that is very difficult for an experienced boilermaker to weld. They can take three times longer to weld. Cheap containers are not always cheap by the end of the job.
- Weld the 10mm base plates to the containers so as you get maximum weld to the container. You can move them about 20mm of the centre line to achieve this, so as the spigot is well anchored. The plans will give welding instructions.
- Weld the spigots to the base plates, aligning with the centre lines.
- If you are accurate with keeping the structure square and the placement of the spigots, then all your “V” braces and longitudinal braces should line up accurately.
- If the fabric structure is outside mounted with partial or full end walls there will be some box steel to weld to the container ends to secure the fabric to.
Step # 3. Joining arch frames
- Your documentation is your best friend when installing fabric structures. Check the plan for the frame sections numbering and placement so components are only moved once to the correct position.
- Place the brace bars on the ground to lay the frame sections on. This will make it easier to move the frames together to join them.
- For web truss frames we use 100mmx100m (4″x4″) trucking timber and put them together in compact stacks. This makes it more efficient for the crane to pick them up.
- Lay out all the frames in the laydown area making sure they are in the correct position, and have the tabs facing the right way according to the plans.
- Distribute the bolts then insert the joining spigots. Sometimes lubricant, WD40 or similar can help, but if you have the frames perfectly lined up they should slide in. If you are installing a second hand unit make sure you wire brush or grind any rust off and give them a thin coat of rust protectant paint. A thick coat of paint can be enough to make them very hard to slide in.
- If you need mechanical help to join the frames use a cumalong (chain winch) with a variety of 2 ton slings 1-3m in length to gently ease them in. Using heavy hammers can result in damage to the structure and protective paint, leading to premature rusting.
Step #4. Lifting the joined frames
- Measure out and mark on the ground the width of the structure next to where the frames are lying.
- Connect the crane to the first frame which will have the tabs for the “V” braces facing towards the crane.
- Place two ropes around the centre of the frame that are long enough to anchor the first frame in place securely once it is in place.
- Space the slings about 1/3rd the way down each side and have a trial lift against the structure width markings on the ground. Adjust the sling spacing if necessary to ensure the integrity of the arch matches the spigot spacings.
- If the structure is over 20m wide you may find, plenty of crane mast height with extra long slings, or a spreader bar for the crane are an advantage.
- Lift the first frame in place and slide it over the spigot or insert the bolts to secure it one end at a time. It may be necessary to wriggle the frame or have the crane move left or right to secure the second end of the frame.
- Anchor the frame with the two ropes so as it is secure. If it is anchored to a vehicle make sure you remove the keys or immobilise it.
- Install the second frame then install all the longitudinal braces. Once these are in place install the bottom “V” braces and several towards the apex. The two frames are now totally secure and the ropes can be removed.
- Install the rest of the frames securing them with one horizontal brace bar about halfway up the side of the arch on each side in two continuous lines. Install more if you have time but these 2 lines will secure the frames.
- When you get to the end, install the “V” braces in both ends and all the other braces.
- Do not tension the brace bolts until all the braces are in place. This can give you up to 15mm adjustment in a 24m long structure which can make installing the braces much easier.
Step #5a. Preparing the fabric cover
- Always when installing fabric structures check the plans for configuration of the tension pipes and fabric.
- For smaller structures that you are going to manually or with the help of equipment pull over the fabric cover. For larger structure we normally lift the fabric and tension pipes up with a crane.
- Check there are no sharp objects on the ground that could damage the cover. If there are cover them with cardboard or other packaging material.
- Make up the tension pipes using flat head tek screws to hold them together and use a couple of rounds of duct tape so they cannot catch on the cover. For smaller structure <20m there are normally one tension pipe on each side. The larger structures will have four or more tension pipes.
- Roll out a short section of the fabric and make sure the tension pipe pockets will be on the inside when you have it rolled out. The side nearest the structure will need to be attached to the container prior to pulling it over.
- Roll out the fabric the length of the structure so as it is even, about 200mm overhang each end.
- Feed the tension pipes into the pockets. Either manually as a whole or in sections or create a pusher bar for a forklift to provide a slow push on the pipe.
- You will need to find the first pocket and install the bar then flip the fabric over until you find the next pocket, to install the next bar.
Step #5b. Installing the fabric Cover
- Lift the near-side tension bar and fabric with ropes so as you can attach 50% of the ratchet straps to their anchor points. The final tensioned placement of the bar will be about 320-370mm so measure 400mm after taking several turns around the ratchet strap. The fabric will then be even when you pull it over firmly.
- Place the ratchet straps on the far side anchor points so as the fabric can be secured quickly once it is pulled over.
- Attach ropes at about 3m intervals to the far-side tension bar. Use 10mm silver rope for 12m wide or less and 12mm rope for larger structures. We sometimes slice the rope about 5m in so it has a “Y” shape so one rope pulls two tie off points.
- Get extra people or vehicles to pull the the cover over. Make sure you have one or two EWPs on the inside to ensure the fabric slides smoothly. The curved pipe pockets are the danger points as if they get wedged into the “V” bracing contact points the fabric will rip if you cannot stop the pull quickly. It is good to have radios but better to have someone standing outside so there is immediate line-of-sight communication between the watchers and pullers.
Step #5c. Managing the wind factors
- We use www.willyweather.com to check the windspeeds on the day of the fabric pull and schedule the pull in the quietest time of the day, often around dawn. A hand held anemometer is used to accurately measure and record windspeed. If you are in for a spell of windy weather for days you can roll the fabric to the centre and place it on top of the apex (see #17) using extra retaining webbing straps to keep it under control in the wind as you lower it.
- Taurus Fabric build will not pull covers if there is 15kph or more wind at apex height blowing into the end of the structure.
- 15kph wind from the fabric rollout side will make the fabric act as a brake as the wind blows it into the frame work. Wait for lulls in the wind rather than put the fabric under high pressure.
- We can handle 20kph pulling into the wind. The fabric will take off like a kite and we use vehicles placed about 5m outside the end line of the structure to keep it centred. The end tension pipe with the ropes attached is also doubled screwed to allow for the extra forces on it and two or three short 5m free hanging ropes that will enable the fabric to be quickly pulled down to the anchor points and secured by the EWP crews.
Step #5d. Rolling the fabric for large structures
- For large structure we mark the dead centre of the fabric apex and roll the fabric and tension pipes into the centre. We will then attach slings at about 25% of the way in each end and lift the rolled fabric to the apex where it is secured with ratchet straps.
- We will then secure four soft webbing straps from anchor-point to anchor-point over the roll of fabric leaving about 300mm of slack in it. Ropes will leave rope burn damage on the fabric.
- Release the apex ratchet straps and unroll about 5m onside then the other side. This is hard work on the relatively flat apex and will require six or eight strong installers. Alternately when you roll the fabric roll several ropes in so as people on the ground can help with the unrolling process.
- Continue to unroll the fabric, one side then the other until you get to the point half way down the arch where the fabric is read to roll by itself. At this stage the fabric on the other side will act as an anchor and the fabric will unroll itself down to the bottom.
Step #5e. Tensioning the fabric for the main cover
- Always secure the fabric quickly with every second ratchet strap once the fabric is in place. At this stage do not tension the fabric, as you need to centre it first.
- Feed the curved end tension pipes into place, make sure it is even, check the fabric sides are within a 100mm of being even then increase the end tension so as the fabric is even but not under tension. Wrinkles in the fabric will alert you to uneven tension.
- Tension the side ratchet straps, using a tape measure to ensure they are level and both sides even and ditto with the end tension straps. If you have upper tension pipes, tension them first then the lower ones. When tensioning the final tension should feel as it has one more click in the ratchet, not tensioned to breaking point. A 36m long structure at 3m distance between frames has 52 tons of pulldown two ton ratchet force between the 2 sides.
- Tension the webbing strap in the end flaps or the joining flaps.
Step #5f. Finishing up the fabric install
- Install the aluminium sail rails to the rope edge and secure the flaps to the containers or gutters if they have been installed.
- Using 500mm cable ties with a small slot in the fabric, make sure that the fabric cannot flap on any of the corners. Free movement will degrade the fabric quickly.
- Well done you are almost finished. Check that all the ratchet straps are tied up neatly, touch up any welds or rub marks and if required seal up the flap edge on top of the container with fast setting foam.
- When installing fabric structures it is critical that you plan the process of installing the fabric and make sure that weather conditions are suitable for attaching the fabric.
Step #6. Installing fabric structure end walls
- At Taurus Fabric Build when installing fabric structures if we need the crane that is installing the main frames to install the end wall frames when we have reached the third section. This will save time in resetting up the crane later.
- Lift the sections and the posts into place and bolt the bottom beam to the container. This is the test for those who placed the container and made sure they were perfectly vertical 🙂
- In the pictured end wall I would attach four rope blocks to the frame and run ropes through them to pull up the end wall.
- Release the tension on the flap if the main cover is fitted so as it is easier to feed the ratchet straps over the end frame. You may also need to back off the first ratchet straps on the side tension.
- Lay your fabric out outside down, and feed the curved tension pipe through the fabric so as it is even. Then attach the aluminium sail rail to the bottom.
- Attach the lifting ropes using a clove hitch so as it cannot slide along the pipe.
- Pull the fabric up with humans or vehicle and attach half the ratchet straps leaving the fabric about 100mm below the frame.
- Use a clamp with padding on either end at the bottom and pull the base taunt before attaching the sail rail to the beam. If you have a light wind the fabric will crinkle and can be up to 150mm too narrow. Make sure you screw the sail rail on so when you tension the fabric upwards, it sits just under the frame.
- Tension the fabric lightly to make sure it is even, then fully tension the fabric. The ratchets should feel as though they will go one more click when fully tensioned.
- Mark the centre line of the vertical posts on the fabric outside and install the aluminium battens.
- When installing fabric structures we normally we install the roof first as a breeze under the cover will make it move by itself as you are tensioning to level. Also if there is an end wind gust you run the risk of a tension pipe puncturing the end wall.