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Under water construction

So whilst many of us think of underwater construction we think of it as a more modern building technique and we think of all the construction in Dubai, however in fact underwater construction actually dates as far back as to 23 BCE where Roman builders constructed the largest artificial harbour ever built in the open sea to date. Caeserea Maritima, where the remains can still be found.

We then have more modern examples of underwater construction like Lake Kariba where construction started in 1955 and was completed in 1959 and cost around 480 million USD.
We also have the world’s first underwater hotel built of the coast of Key Largo Florida which was actually a research facility dating back to the 1970’s La Chalupa Research Laboratory which has been converted into a hotel, named Under The Sea Lodge which opened it’s doors to guests in 1986. This building is completely underwater and is only accessible by scuba diving more than 6 meters down and gaining access via a “moon pool” which is located under the building.
We then have the mega structures in Dubai where they have taken underwater construction to new depths constructing islands and underwater hotels and water theme parks like The Palms and Atlantis.

So how does one actually build underwater?
Well you have to firstly create a stable and dry environment in which to build in order to work in the environment and place concrete in it.

We have basically two different methods / techniques in which to build underwater.
Firstly we have Cofferdams, which are temporary structures normally used where the construction area is larger and the water depth less, you also get different types of cofferdams.

• Earthen cofferdams,
• Doubled Cofferdams
• Rockfill Cofferdams
• Single walled Cofferdams
• Crib cofferdams
• Cellular cofferdams

Cofferdams are normally used for constructing bridge piers and other supporting structures

Then you get Caissons which are more permanent large hollow watertight structures which are used for repairing bridge foundations and dams.

You also get different type of caissons, namely:

• Box Caissons
• Open Caisson
• Suction Caisson
• Pneumatic Caisson

A good example of construction using Caissons is the Port of Ngquru just outside Port Elizabeth, which used 5 Caissons anchoring the ends of the breakwaters which required 18 000m³ of reinforced concrete.

So whilst there are different types of underwater construction it remains quite a complex and challenging construction method testing the boundaries of construction in general.

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About Jennifer Ellis

I Started working with Leads 2 Business in 2007 and been based in Port Elizabeth as a Senior account Executive. I oversee the Subscriber base in the Port Elizabeth and surrounds region as well as some National subscribers.

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Demolition

Demolition is the destruction, knocking down, pulling down, tearing down, flattening, razing, levelling, bulldozing, clearance, obliteration and annihilation of buildings and other man-made structures, however, it has been known that when one is stricken with immense hunger, one can demolish a whole pizza in one sweep.

Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for re-use purposes.

Demolition Plan:
For small buildings, such as houses, that are only two or three stories high, demolition is a rather simple process.
The building is pulled down either manually or mechanically using large hydraulic equipment: Elevated work platforms, Cranes, Bulldozers, Backhoe Loaders & Hydraulic Excavators.

Larger buildings may require the use of a wrecking ball, a heavy weight on a cable that is swung by a crane into the side of the buildings. Wrecking balls are especially effective against masonry but are less easily controlled and often less efficient than other methods. Newer methods may use rotational hydraulic shears…

Used for cutting steel, cable and rebar and silenced rock-breakers attached to excavators to cut or break through wood, steel, and concrete. The use of shears is especially common when flame cutting would be dangerous.

For larger buildings or structures, however, it is imperative to make sure there is a plan in place. One thing about construction projects is that just as they went up, someday they must come down.

When that day arrives and the building has become unsafe or just seen better days, it’s time to call in the demolition experts.

First they need to assess your needs as there are many different factors involved in a building demolition and several different ways to go about it. Once your needs are determined, a plan is created. The plan will include how the demolition is to be carried out as well as all the equipment that will be used to do it. The ultimate goal is to get the building demolished in the safest and most efficient way possible. These decisions will depend on the size of the building, the building materials, the reason for the demolition and the location of the building.

Some methods that will be considered include:

1. Implosion

Large buildings like the World Trade Centre, tall chimneys, smokestacks, bridges, and increasingly some smaller structures may be destroyed by building implosion using explosives or terrorist trained pilots. Imploding a structure is very fast—the collapse itself only takes seconds—and an expert can ensure that the structure falls into its own footprint so as not to damage neighbouring structures. This is essential for tall structures in dense urban areas.

Any error can be disastrous, however, and some demolitions have failed, severely damaging neighboring structures. One significant danger is from flying debris, which, when improperly prepared for, can kill onlookers.

Another dangerous scenario is the partial failure of an attempted implosion. When a building fails to collapse completely the structure may be unstable, tilting at a dangerous angle, and filled with un-detonated but still primed explosives, making it difficult for workers to approach safely. A third danger comes from air overpressure that occurs during the implosion. Stephanie Kegley described shock waves by saying, “The shock wave is like a water hose. If you put your hand in front of the water as it comes out, it fans to all sides.” When cloud coverage is below 1,200 feet, it reacts like the hand in front of the hose. The wave from the shock fans out, instead of up toward the sky. If the sky is clear, the shock wave, a wave of energy and sound, travels upwards and disperses, but if cloud coverage is low, the shock wave can travel outwards, breaking windows or causing other damage to surrounding buildings.

Controlled implosion, being spectacular, is the method that the general public often thinks of when discussing demolition; however, it can be dangerous and is only used as a last resort when other methods are impractical or too costly

2. Deconstruction

A new approach to demolition is the deconstruction of a building with the goal of minimizing the amount of materials going to landfills. This “green” approach is applied by removing the materials by type material and segregating them for reuse or recycling. With proper planning this approach has resulted in landfill diversion rates that exceed 90% of an entire building and its contents in some cases. It also vastly reduces the CO2 emissions of the removing of a building in comparison to demolition.
Timber waste can be shredded using specialist timber shredders and composted, or used to form manufactured timber boards, such as MDF or chipboard.

3. Selective Demolition

This is used rather than flattening structures in one fell swoop which maximizes efficiency by reducing waste, repurposing reusable materials, and lessening environmental impact. This approach works hand in hand with Deconstruction.

Carrying out the plan
Once the plan is set, the demolition company will know the method, the equipment that’s necessary, the approximate cost, how much debris there will be, how it will be dispersed at the site and how long it will take to clean up. Back up plans and emergency plans will also be part of the overall demolition plan. After the plan has been finalised the company must get all necessary permits so they are safe when the demolition is carried out.

Like any job before the fun stuff begins there’s the preparation work that needs to be done and so site preparation is just as important as the demolition itself. The building must be completely cleaned out of the utilities like gas, water and electricity as well as the removal of hazardous materials.

After it’s all planned, legal aspects are covered and the site is ready, the demolition is scheduled and carried out. To some people seeing a building demolished is a thing of beauty.

The co-ordination and expertise that goes into pulling it off just right is truly staggering. In a lot of ways the building going down isn’t really an ending but a new beginning…

Sources:
https://en.wikipedia.org/wiki/Demolition
https://theconstructor.org/structures/demolition-methods-process-buildings-structures/13941/
https://en.wikipedia.org/wiki/Backhoe_loader
https://en.wikipedia.org/wiki/Excavator

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About Helga Venter

My name is Helga Venter. I started with the company in 2004 and was promoted to Financial Director in 2007.

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Safety when using heavy machinery

One of the main dangers on the site is the heavy machinery used for various projects. Safely operating these machines is of the utmost importance. Staying calm and alert throughout the day will allow for more productivity and will translate into a positive working environment for all those around you. If you work in construction, you know that working on a construction site can be one of the most dangerous and hazardous jobs out there. Proper safety starts and ends with your decisions and how you conduct yourself.

TRAINING
It is of paramount importance that all operators have identifiable and verifiable training on heavy equipment before operating. Accidents can occur to both the newly trained and seasoned veterans.
Workers should be trained on the proper procedures to safely operate all pieces of equipment they will be working on. Training should be conducted as a combination of classroom and practical hands-on instruction. Topics that should be covered include safety, hazard identifications, safety features of the equipment and safe manoeuvring of the heavy equipment.
Workers should be trained on how to safely mount and dismount and the proper start up procedure for each piece of equipment. They should have a clear understanding of lifting loads and load capacity for the equipment they will be working on. Retraining and refresher courses should be conducted as needed, especially if a worker is observed operating equipment unsafely or in a manner other than its intended purpose. Only trained workers should be allowed to operate equipment for any reason.
Working with or around heavy equipment should be part of your overall safety program. All workers should be trained on the dangers and hazards of working with heavy equipment. Staying knowledgeable and safe with your equipment is a sure-fire way to make sure you’re protecting yourself and your co-workers.
Conduct a visual inspection before use
Visually inspect heavy equipment before each use to ensure it’s in good operating condition. Equipment must be inspected at least once a day before operating. This must involve walking around with a checklist of components to check for good working order.

KEEP THE AREA CLEAN Ideally, you can cordon off the area with barriers to keep workers from accidentally getting in close proximity to operating equipment. If you are moving or operating equipment near workers use a spotter, using radio or hand signals to communicate, to keep your blind spots clear. This is especially important when backing up. Yes, the equipment will have backup alarms, but they often go unheeded on construction sites due to their prevalence. Blind spots Operators of heavy machinery have to be 100% sure that no one is behind them or in their blind spots when moving, even if this involves getting out of the machine and checking. If vision is limited, have a spotter stand in a safe, visible position to guide and direct you. Inform those working around you for the day of your blind spots and require them to make eye contact with you before coming in the equipment’s vicinity. High visibility vests are mandatory on all sites.

COMMUNICATION In all aspects of life, communication is perhaps the most important way to drive results and meet deadlines. When working with heavy machinery, communication is just as important. Creating safety policies and procedures for your machines and making sure you constantly communicate them can save lives and money in the long run. Stay on top of workers who are not working with safety procedures in mind, and make sure they know about all of your policies. Be in constant communication with those working around you. A two-way radio is the best form of communication, if that option is not available then use hand signals from a spotter who has been properly trained. Communication with operators should be touched upon at every safety meeting and reinforced by the foreman on site.

SEATBELTS / PPE Wearing your seatbelt in heavy equipment is just as important as wearing one in a moving motor vehicle. There is no excuse for not wearing it at all times. Not only can it save your life, it will keep you firmly in your seat. Always wear proper personal protective equipment (PPE) such as gloves, safety glasses, sturdy boots and hard hats.

LOADING / UNLOADING EQUIPMENT Always be sure to be on level ground when loading or unloading your equipment. It greatly reduces the risk of rollovers or sliding off the low-bed ramps. If unloading on a busy jobsite or high traffic area, make sure people are clear of the unloading area and use a spotter to guide you. Overhead and Underground Hazards Before work begins on any jobsite, over-head obstructions such as power lines and low clearance should be identified and flagged. Underground utilities like water, sewer, gas, and electrical need to be located by the appropriate department and marked with colour coded paint. Play it safe when getting close to the underground utility and hand dig to uncover. When leaving dugout holes that workers or the public can fall in to, be sure to set up barriers and snow fencing.

LOCK-OUT / TAG-OUT
According to OSHA, employers must train and have procedures in place to ensure that before any employee performs servicing or maintenance on a machine where unexpected start-up or release of stored energy could occur and cause injury, the machine or energy source must be rendered inoperative. This includes hazards such as pinch points, attachments, and raised loads. Picture warnings, locks, and tags must be utilised to prevent any incidents.

LOAD LIMITS
Always be aware of the load limits of varying equipment when operating different machines throughout the day. Depending on the equipment set-up and size the load limits can change. When lifting objects with a machine make sure loads are secure with the proper rigging attachments, and always inspect to ensure they are in good working condition. As with most equipment operations, confirm that all workers are at a safe distance when lifting and moving loads. When loading and unloading equipment at the site, make sure you do it on level ground to avoid rollovers when getting it on or off the truck or trailer.

WALK-AROUND INSPECTION
Equipment must be inspected at least once a day before operating. This must involve walking around with a checklist of components to check for good working order. Hydraulic hoses, undercarriage, oil levels, stress points, etc. are all areas that need to be inspected and reported to the maintenance/safety department before machine start-up. Using a cloud-based mobile device to complete a task such as this can greatly improve communication and response time between operator and mechanic.

BE AWARE OF YOUR SURROUNDINGS
When operating heavy equipment, you need to mindful of the area you are working in and any obstacles you may encounter. Overhead power lines should be deenergized, or if that’s not possible, establish barriers to avoid making contact with them. If digging, make sure that all underground utilities, such as sewer, water, gas and electrical, have been identified and clearly marked to avoid damaging them and creating delays and more work.
Whenever possible, workers should be kept out of areas where heavy equipment is in operating. Operators should be aware of their swing radius, especially when working in tighter spaces, to avoid hitting other workers, bystanders, or other vehicles or equipment in the vicinity.

ENTERING AND EXITING EQUIPMENT
This one should go without saying, but based on the number of injuries workers suffer each year, but there is a right and a wrong way to mount and dismount from heavy equipment. When climbing onto equipment, always maintain three points of contact just like you do when climbing a ladder. Never carry anything with you as you enter or exit.
Never enter or exit equipment that is moving or in operation. Make sure you completely shut off the equipment, engage the parking brake and release any pressure from hydraulic controls. Make sure to take the keys with you to avoid any unauthorized use.
Only use equipment for its intended purpose
Each piece of equipment was designed to perform a specific task. Excavators aren’t cranes and wheel loaders weren’t made to carry workers in the bucket and used as an aerial lift. Pick the right piece of equipment for the task at hand and use it as the manufacturer intended.
Don’t overload or overwork equipment. Be mindful of the payload or lift capacity of the equipment. This may require getting a bigger piece of equipment if what you have isn’t enough to get the job done. If lifting material, make sure all riggings are properly secured. Don’t try to go too fast when operating equipment, especially on slopes.

SLOW IT DOWN
There always are deadlines on any project, which is why you experience stress to get the project done. Unfortunately, one of the largest causes of accidents on construction sites is due to people moving too quickly. Avoiding an injury or accident is as easy as taking your time, and making sure you’re being safe and smart about the machines you’re using.

Sources:
http://www.ehstoday.com/construction/5-tips-safely-operate-heavy-machinery
https://nektardata.com/top-ten-heav y-equipment-safety-tips-for-incident-prevention/

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About Lola Govender

My name is Lola Govender. I have been working at L2B for 14 years and am very passionate about our business.

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The importance of dry and wet hire.

Did you know that you get what is called “wet and dry hire” when hiring equipment?

I knew none of this and this topic had me stumped for a good couple of hours.

Did you know that wet hire is when you hire your equipment with an operator and all you would need to keep the equipment fully operational, this also includes the diesel you would need throughout your project?

Where dry hire is when you just hire the equipment and not the operator and added benefits.
This also means that the diesel is not included: however you do get the machine with a full tank of diesel but when you return the machine you need to return it with the same amount of diesel as it arrived with.

After some reading I do see that both wet and dry hire are good to have in their own way depending on what type of project you are busy with and how big your project is.

The advantages of wet hire:

• Cost effective (bigger projects).
• Operator has knowledge of equipment.
• The diesel that you would use is included in the hire of the machine.
• No added cost when equipment needs repairs keeping cost down and your project on track.
• Removes the stress of hiring other people to operate the equipment.
• One quote – one price.

The advantages of dry hire:

• Save money by keeping your labour within the company.
• Not many people on site.
• When you use someone that works for you they have an understanding of how you work and what you are wanting done on site.

Wet and Dry hire both have benefits depending on the given situation. When planning your next project make sure to take all aspects in to account when hiring machinery.

Sit down and think of what you need done – Will it be better to get wet or dry hire?.

Sources:
• https://www.linkedin.com/pulse/wet-hire-vs-dry-whats-best-general-hire-group/
• https://blog.plantminer.com.au/pros-and-cons-of-wet-and-dry-hire
• https://www.humehire.com.au/wet-hire-dry-hire/

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To view notes with screenshots on how to use our website, please visit our Wiki site.
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About Tamika Mays

I started working at Leads 2 Business the 7th March this year. I have been working in the Leads to Quotes department where we deal with the contractors on a day to day basis. We help the contractors get the pricing they need for the contracts. The construction industry is an ever evolving industry and I love learning new things every day. Leads 2 Business is an amazing company to work for and is filled with amazing staff.

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