Archive : Category

Hydrodemolition – The Importance of PPE

POSTED ON February 19th  - POSTED IN Blog

At Sabre Jetting Services Ltd we provide our operators with the latest and most relevant hydrodemolition PPE available. Over the years it has been a challenge to find suitable PPE for such a small and specialist industry and we have even had to develop our own in order to ensure our operators are protected to the highest available standard. As you can see if you watch some of the videos on our website, our operators work in enclosed areas with concrete debris bursting off towards them at high velocity as they remove it. In addition to the flying concrete debris, the operators are also working in wet conditions and utilising potentially dangerous (if used incorrectly) high pressure water within close vicinity of their body. PPE is a crucial part of a system of control measures put in place to protect the operators from the potential hazards of their working environment.

In view of the necessity for suitable PPE when carrying out hydrodemolition, Sabre Jetting has committed considerable time and money into finding the finest PPE available. This search has included trials by our operators, development committees, independent testing and the creation of technical files for CE certificates of conformity. Although we are currently satisfied that we are using the best PPE available for this niche industry, we continue to look out for progress made by the suppliers and to look at ways develop the PPE which is created in house.

Items of PPE

All of our operators are issued with their own pair of TST High Trousers which offer protection against the water jet. These have been selected as they are rated up to 3000 BAR and are most likely to offer protection should the operator swipe himself with the lance. We have found from using the TST High Trousers and other similar products that the TST PPE offers greater comfort and range of movement than the other products therefore allowing the operator greater control of the jetting gun.

The wellingtons worn by our operators are chainsaw wellingtons which have a steel toe cap. Although there are two specialist water jetting wellingtons on the market, they have been found to be unsuitable for a hydrodemolition environment and fail to provide the primary function of a wellington, keeping the feet dry. The wellingtons we provide are selected for their durability and high slip resistance.

Wearing a chainsaw wellington rather than a water jetting wellington poses one problem, and that is how to provide enhanced metatarsal protection. For this we have found that the Falch Foot Protectors are the optimum solution. The Falch Foot Protectors have been selected following extensive trials of metatarsal protection. Three alternative options have been discounted following trials due to their unsuitability when carrying out hydrodemolition. The Falch Foot Protectors are found to be easy to secure to the wellington with good coverage of the foot. Operators have reported that they stay in position during jetting and do not provide any limitation on movement. All our operators are issued with their own Falch Foot Protectors and wear them on every job we carry out.

An integral part of the PPE provided to our employees is the two piece wetsuit. As you can imagine, you could get rather wet when carrying out hydrodemolition and this wetsuit is therefore essential to keep the operator dry whilst also protecting the legs, arms and torso against rebounding concrete debris. The wetsuits we provide are Scandinavian manufactured heavy duty fishing wetsuits and stand up well to the rigours of hydrodemolition. An alternative lightweight wetsuit is also available for use when carrying out less aggressive applications. Operators are issued with new wetsuits every 6 months or, sooner if any damage occurs during wear.

Due to the noise levels created by the water leaving the jetting nozzle at high speed, all hydrodemolition operatives must wear hearing protection. In order to find the preferred product, we tested a number of ear defenders with SNR ratings high enough to reduce noise exposure to the required levels. Following feedback from the operators a HL ear plug was selected based on comfort, and ease of use, but also ensuring that the product gave the necessary attenuation at the noise frequency created by the water jet.

Possibly the most critical item of PPE for a hydrodemolition operative is the jetting mask. This item offers protection to the eyes and face from flying concrete debris. Despite being such a vital piece of PPE there is nothing available off the shelf from the major PPE manufacturers that is suitable for use in the hydrodemolition industry. Sabre Jetting Services have therefore developed our own mask which has been independently tested and deemed to meet the requirements of EN166-B, the standard for protection against high speed particles. Each mask is manufactured to a strict standard following instructions set out in the product technical folder, ensuring our operators are always using a mask made to the highest possible standard.

In order to guarantee our operators have the correct PPE at all times, Sabre Jetting Services conduct meetings twice a year to issue and inspect PPE. Operators are also encouraged to return any damaged PPE for replacement as required.

What is hydrodemolition?

POSTED ON December 16th  - POSTED IN Blog

Hydrodemolition is the controlled removal of concrete using high pressure water. Despite the name hydrodemolition, the technique is used mainly for localised concrete removal on civil engineering contracts rather than for traditional building demolition. High speed water penetrates cracks in the concrete and the hydraulic effect causes the concrete to burst into smaller pieces. A brilliant example of this can be seen on our homepage; a slow motion video of an operator using a hand held lance to remove concrete to a deck. The video shows the operator maintaining the position of the water jet on the concrete allowing the water to break away the concrete at its weakest point.

Hydrodemolition can be used for a wide variety of applications, from intricate removal around bearings, to mass demolition of decks, piers or parapets. Operators will select different pressures to suit each task. For instance, when removing bearings, a lower pressure would be selected to allow the operator to manoeuvre the jetting lance around the bearing plate and bolts and to breakout to the back of the bearing shelf. Alternatively, when removing concrete to a deck or a parapet, a higher pressure can be utilised as the operator allows the brute force of the constant water jet to hammer away at the concrete. At Sabre Jetting, we have vast experience of all types of hydrodemolition and always apply the optimum techniques to ensure work is carried out as safely and efficiently as possible on every contract.

The main reasons for selecting hydrodemolition as a method of removal are to keep steel reinforcement intact, or to avoid any vibration to the rest of the structure from which the concrete is being removed. When removing concrete with high pressure water, no damage whatsoever is caused to the steel reinforcement by the water jet, making this technique ideal for repair contracts. The water will only cause destruction at the point at which it hits the surface of the concrete meaning the rest of the structure suffers no adverse consequences from the removal. A further benefit is that when hydrodemolition is used, a rough finish is created on the remaining concrete, giving the ideal bonding surface for the new concrete.

As well as not causing vibration to the adjacent structure, the operator of a hand held lance will also not suffer any vibration when carrying out hydrodemolition. An independent report by the British H&S Laboratories found that operators will not exceed the exposure action values when carrying out high pressure water jetting with a straight jet. This means that hydrodemolition is therefore preferable to using hand held mechanical tools. This has led to a large increase in the use of hydrodemolition as an alternative to jackhammers.

Hydrodemolition Projects

Repairs

Hydrodemolition is often used on repair contracts to remove damaged or failing concrete in varying sized patches whilst leaving the sound concrete intact. A survey will be carried out to determine the areas of concrete to be removed. Hydrodemolition will then be employed to remove the patches, exposing the reinforcement and allowing repair concrete to be sprayed or poured back. The top layer of the concrete is removed first, followed by breaking out behind the bars to ensure the replaced concrete effectively repairs each location. Repair works are often carried out on piers, abutments and soffits of bridges as well as on jetties and concrete tanks. Details of major repair projects we have carried out at Newport Jetty and on the Midland Links can be found on our projects page.

Bearings

Another common application for hydrodemolition is to allow the removal of bearings used to support bridge decks. This can be straightforward where there is good access and plenty of room to work. However, this is often not the case and the breakout can be highly technical and physically demanding. Where there is little room to work due to the design of the structure, a lance shorter than the standard minimum may be required. If this is the case, the situation must be assessed to ensure there is no other option but to use a shortened lance. Sabre Jetting has stringent procedures in place for such scenarios and all operators are trained on these procedures.

Piles

Sabre Jetting has carried out numerous pile projects over the last 30 years. Hydrodemolition is used to reduce the height of the piles to the level that the contractor requires. The contractor will sometimes demolish the top of the piles, as far as possible, using conventional means and then hydrodemolition is used to complete the breakout and save the required amount of steel.

Large Scale Removal to Parapets, Decks & Piers

Parapet removal projects are often higher volume than many other projects. The requirement may be to upgrade the existing parapet or to remove the parapet to allow a widening of the bridge. Using the best equipment available, we are able to achieve outputs of up to 2m3 per crew on this type of removal. Similar rates of removal are possible on deck removal projects as the removal technique is almost identical. Where pier projects are concerned, hydrodemolition is commonly used for repairs as mentioned previously. However, as demonstrated on our projects page, major controlled demolition of piers can be carried out using water jetting, as with the M27 Junction 9 and the A1260 Bridge structure projects.

The projects described are common applications for hydrodemolition but by no means an exhaustive list. If you have any questions about hydrodemolition or in relation to an upcoming hydrodemolition project, please feel free to contact us and we will be more than happy to offer our expertise.

Sabre Jetting Services maintain Investors in People Bronze Award

POSTED ON November 20th  - POSTED IN Blog

We are delighted to announce that following assessment by John Jones of EBM Excellence, on behalf of Investors in People, Sabre Jetting Services continues to meet the standards required for the Bronze Award.

Having achieved Investors in People standard in 2005 we decided to take the next step during our third assessment in 2011 and aim for the Bronze Award under the Investors in People extended framework. In providing his report in 2011, Assessor John Jones wrote ‘The recognition and the award are notable achievements for a small organisation operating within a sector that has suffered severe constraints within the current economic climate – the senior management’s commitment and investment in their people and business is commendable’. We are therefore extremely happy to have continued to meet the standards required for the Bronze Award and that the continuous improvement within the company has been recognised once again.

We would like to highlight the significant contribution of our workforce in achieving this award. Their effort and commitment, along with a willingness to buy into the goals of the company, play a huge part in showing the company in such an excellent light.

We now look forward to receiving the full report from John Jones and utilising his feedback to develop further over the next three years.

Sabre Jetting Services featured in BBC 2 Documentary

POSTED ON September 19th  - POSTED IN Blog

Sabre Jetting Services recently appeared in a BBC 2 documentary called The Motorway: Life in the Fast Lane, aired on 16th September 14. The documentary series is a look into the motorway system around Birmingham and examines the role of workers that help to keep traffic flowing around the UK’s second city.

 

During the second episode of the series titled ‘Keeping the Show on the Road’ there was a large focus on the maintenance of the road system, including the repair works continuously carried out to ensure the integrity of the vast concrete structures carrying millions of vehicles each year. As a sub- contractor carrying out a key element of the repair works; the hydrodemolition of concrete repair locations beneath the elevated carriageways, Sabre Jetting’s operatives were filmed going about their daily routines on the R163 contract, the most recent of numerous Midland Links contracts completed by Sabre Jetting over the last 25 years.

 

The team on site, Richard Donnelly & Daniel Horsnett, were shown during the documentary informing the viewers of the PPE they wear and the reasons it is required. The programme then cuts to shots of the hydrodemolition in action and close ups of the water jet penetrating the concrete at high velocity. Richard and Daniel are two of the most experienced operators in the country, especially when it comes to Midland Links work. As a company, Sabre Jetting have worked on 12 of these major projects over the last decade alone and are unrivalled in their ability to carry out this type of technical work.

The programme, The Motorway: Life in the Fast Lane ‘Keeping the Show on the Road’ will be available on BBC iPlayer until 16th October. Look out for Sabre Jetting in action from 16m 30s into the episode and for further information on hydrodemolition and the other services we offer, contact us now on 0121 706 9801.