Advantage mechanisation
Tougher norms for quality and safety in high-rise construction have pushed the contractors and developers towards advanced mechanisation for building quality structures within the set time line. The basic advantages of mechanisation are: achieve faster project completion, safe execution of projects, and can construct the project to the set safety and quality parameters.

A person working without fear can be more accurate and productive in his job. Dr Ahamed Mohideen, Deputy Vice President - Plant & Equipment, Lodha Group, says, ?Anybody who works at a height of 200 m and above will have a sense of fear. When you have proper mechanisation in place with all the safety aspects inbuilt, then people can work with free of fear, which can improve the efficiency and productivity of the people.?

More technology means added cost to the machine. Every value addition done in any machinery demands more cost. Vikram Mehta, Managing Director, Spartan Engineering Industries, highlights the value of the machine above its cost, as he says, ?It is time to rise above cost and see the value you get from the machinery. Spartan machines are well equipped with all safety features, which make them the most reliable and safe construction equipment and the premium ones too. We provide machines with various optional features as well, which make them affordable and cost-effective. These machines include various models in bar cutting and bending machines, rope suspended platforms and man and material hoists.?

Equipment/technology trends
Dr Mohideen elaborates, ?We use climbing formwork systems, which is one of the vital mechanical elements coming into Mumbai for high-rise constructions. Accessing people and materials is of prime importance in high-rise construction projects. For people access, either a passenger hoist or a kind of access climbing method is needed. MCWP is one of the safest methods of doing access to high-rise structures.? For the material movement, normally everything is done by tower cranes. ?Especially in high-rise projects, we go with luffing tower cranes which can be used free from the restrictions of other buildings all around. There are no trolleys in luffing tower cranes so that it will occupy less space, and it will have maximum lifting capacity,? states Dr Mohideen.

Spartan offers Aviator series of rack and pinion man and material hoists in various models of carrying capacity, right from 500 kg to 2 tonne. It also comes in single- and twin-cage options. These machines are used at both medium- and high-rise structures. Mehta elaborates, ?Spartan?s multifunctional hoist replaces tower cranes for rebar lifting application, thus saving on huge investments. This hoist has a rebar carrying attachment, which carries rebar measuring 12 m through horizontal rebar attachment. Spartan also plans to manufacture twin-cage hoists in a year, which is at design stage. All these safety features make Spartan?s hoists more reliable and competitive.? In aerial work platforms range, Spartan manufactures Rope Suspended Platforms (SRP), popularly known as Gandola. Spartan is a market leader in SRP and it is used for various finishing applications like plastering, putti application, painting etc, at the end of the project.

Concrete pumping has become a challenge with the structures are going taller. Schwing Stetter is a major player offering solutions for concrete pumping to higher levels. The company has recently introduced SP 4507 concrete pump at Bauma Conexpo India on this note.

VG Sakthikumar, Managing Director, Schwing Stetter Sales and Services, elaborates more on product range, ?Our other major products for these projects are heavy-duty concrete pumps - SP 3000 to SP 8800 - which have bigger capacity twin-circuit concrete pump and are suitable for pumping higher grade concrete M60-M95 to 400 m height and above. Concrete output range is from 30 cu m/hr to 90 cu m/hr. New generation rock valve technology handles high grade mixes and patented cleaning methodology by Schwing washout, the concrete pipeline system.?

He further adds, ?We offer S20, S36 X, and S43 SX truck-mounted boom pumps which have 2016 and 2023 pumping kits for modulation of concrete output, use single and twin-circuit for rock switch over modulation. Separate placing booms 25, 28, 30, 32, 35 m offer easy and fast placing of concrete. It has articulated boom which are lighter and can quickly be erected and dismantled. Circular distributor RVH 18 is also used for concrete placing.?

Globally, Schwing group is a pioneer in high rise construction. Sakthikumar elaborates, ?Most of the world famous construction records for high rise structures are available with the Schwing concrete pumps. These buildings exist across the continents, including the most recent Kingdom Tower which is planned to be constructed in Saudi Arabia at a height of about 1,000 m. Our experience globally helps us to identify or anticipate the problems that could come in Indian sites. In India, we are today talking about high-rise projects between 200-450 m height. So the problem in India is relatively easier to solve with respect to the dimensional challenge for a high-rise project.?

Safety
Mehta elaborates on the safety features associated with Spartan?s range, ?All our hoists come with centrifugal safety device, which activates by centrifugal force and stops the hoist in case the hoist?s speed exceeds beyond a limit. Many such safety factors are part of our every single machine. Control panel in the hoist is one of the most advanced features of our hoists. It is provided with flash light for easy visibility, joystick for easy operation and emergency switches. The PLC functions cover a lot of indicators like VFD trip, limit switch failure, phase failure exit door, open entry door, rack search fault etc. The higher/premium models also have a display screen, where the actual fault would be displayed for easy identification and repair. It is placed at a strategic position which would be easily viewed by the operator. These machines also come with mechanical lock and electrical sensors in critical areas like entry/exit door, trap door, erection platform etc. This ensures hoist does not start if any door is left open. To add to these, overload alarm indicator is also provided as an option. SRPs come with various safety features like anti-swing device. This is one of the most advanced features of Spartan?s SRP, where it holds on the SRP, avoids swinging of SRP at higher heights and ensures operator?s safety. Our SRP also comes with roof attachment, where the SRP and the operator are safe from the falling debris or material from top while working. All these safety features in our machines display our commitment towards customer?s safety at site.?

Sakthikumar comments, ?Safety in any construction is very important. The role of safety is crucial in a job site wherein communication among the team members decides the success of a project to be executed. We offer inbuilt emergency system in all our equipment for stopping the machine operation in emergency conditions. Special features like pressure indicating system in concrete pump segment provide the indications of machine behaviour, concrete behaviour with respective pressures and hopper grill safety is inbuilt to avoid accidents. Another example is using a Schwing-XCMG tower crane is that it is an external type tower crane that can be used as an inner climbing tower crane also.?

According to Dr Mohideen, irrespective of height of the structure, safety system is required in every project. He comments, ?Falling can be fatal even if a person falls from a height of 3 m. So it doesn?t mean that you keep safety measures for only high rise projects. Contractors should think that people?s life is very important. So, safety should become an inbuilt system. There are safety measures taken in high rise towers, however, in lower height structures also the mindset should change and sufficient safety steps need to be taken by the contractors and become more safety conscious.?

Technology adoption and implementation
According to Mehta, construction equipment market has always been volatile. He says, ?A lot of ?me too? and substandard cheap imported machines have been a threat to Indian market for some time now. But, we understand that only a stable and consistent brand can be the winner in long term. Price war has always been dictating the orders, but we haven?t moved away from being the safest and the most reliable brand in construction equipment industry.?

He further adds, ?Being the market leader for more than a decade now, we understand the market requirements very well. Customisation in machines has been prevalent for a long time. Hence, we do a lot of surveys and site inspection before we suggest any machine to our customers. Every site calls for different challenges and we provide solutions through our machinery, which suits the best for every site condition. The best way to attend to cost-competitive market is to provide the best value for the cost. We always strive to give maximum value to the customer, so much as to compete on the values offered and not at the cost charged. This keeps us above our competition, keeping the customer?s requirement on our top list.?

Challenges
Sakthikumar explains the challenges of handling concrete, ?With respect to concreting in high-rise project site, time constraints are becoming a major challenge. There are different situations in high-rise construction. Construction at below ground level like diaphragm wall or raft foundation pouring, we find the volume of concrete required is very high. In this situation, the concrete required at site is enormous and we have to depend on batching plants not only in the site, but also the neighbourhood RMC concrete supplying to the project site.?

He further adds, ?In city limits, transportation of concrete through concrete mixers towards the site from outside is practically impossible due to heavy traffic. Even with the batching plant inside the construction site, bringing the raw material is only possible during the night and it is not possible in the peak traffic time. So all these have to be planned and executed.?

Market opportunities
According to Sakthikumar, the market opportunities lie in the fact that high-rise construction in India is relatively new. It is there for the last five years. He says, ?About 90 per cent of these projects are restricted to Mumbai, while the rest outside Mumbai, like in NCR and Kolkata. But we expect the trend to change in future and India will see more high-rise structures.? With the rural population migrating to urban area, the land cost in core urban centres are going to escalate further. High-rise structures is the solution to compensate this cost escalation because the construction cost per sq ft will share the cost with the land area. ?We expect more high-rise projects to come in the six urban clusters in India. We also expect once the smart city projects see implementation, the requirement of high-rise construction to grow even further,? Sakthikumar observes.

Training imperative
According to Dr Mohideen, a major aspect to understand is that people who are implementing new technologies should also make their teams to be properly trained and do only the safe works. He observes, ?In the recent past, there were accidents of crane fall which happened because of lack of knowledge, training and the people without the required qualification being inducted into the job. This should be avoided. More training centres should be created in-house as well as outside to give proper training to the operators so that the technology gap in the market can be completely avoided. Training and development should play a major role in future because the availability of trained crew is becoming a concern and people are forced to work with teams without much exposure to the mechanised systems.?

Sakthikumar says, ?A major challenge in India is the knowledge level of general workmen who are associated with these types of project as they do not have long years of experience in executing projects of high rise nature. So, we have to be careful to teach them safety, quality and cost-effectiveness in executing a project of this nature.?

Emerging scenario
According to Mehta, high-rise constructions have been seen coming up across regions in India. He states, ?High-rise structures have already moved from metros to tier 1 cities and now penetrating into tier 2; and tier 3 will catch up soon, considering various new government policies. The trend is also slowly shifting from usage of obsolete builder hoists and scaffolding to safer and reliable options. But, at the same time, considering the recent pace of the projects and cost involved, customers are expecting more flexible, multi-functional and safe machinery. Spartan has been pioneer in manufacturing such machinery, be it our multi-functional material hoists to the ?to be soon launched multi-functional mini lift?. Our SRPs too are doing really well for various applications like plastering, painting, fatade applications and maintenance. Our recent commissioning of SRP at a project height of 250 m is one of the examples.?

According to Dr Mohideen, awareness of safety is increasing in India because now if any casualty happens at site, people will be questioned and government is also strict making safety norms for the construction projects. India is also moving towards the global project timeline system. He adds, ?Earlier one slab used to take 21 days for completion. Now people try to achieve a slab cycle of 5-6 days for the high rise towers. So, accordingly all the mechanical systems need to be in place. So, in that way, all these mechanical systems facilitate to complete the work as per the project requirements.?

Outlook
Says Dr Mohideen, ?In high rise construction, definitely there is a major change today from what was there few years back. And bigger developers like Lodha Group want a perfect safety set with completely mechianised and modern systems used in all the sites.?

With the government?s various initiatives, high-rise construction will be on a continuous growth path in the coming years. Big project developers and contractors, of course, are bound to use innovative advanced equipment for safe and quality construction.

TRENDS IN HIGh-rises and concrete pumping
Realty
Rapid construction and very fast cycle time.
Residential tower height rising 375 m and above.
Concrete pumping is going on an above average 200 m height with high grade concrete of M95, higher capacity concrete pumps are needed and mechanised separate placing booms are required to place concrete of high speed.

Infrastructure
Roads and bridges: Use of truck-mounted boom pump is one of the trends for pouring bridge concrete. Height and length of the bridges are continuously increasing, for e.g., the height of Chenab Railway Bridge is 359 m from the river bed and 1.3 km in length. For doing pumping of special concrete in large quantum, high rate of output and highly efficient concrete pumps and placing equipment are required.

Special structure: The construction of Statue of Unity in Gujarat in remembrance of Sardar Vallabhbhai Patel is under construction wherein the height of the statue is 182 m. Schwing Stetter concrete pumps are pumping high grade of M65 concrete for this project, and SPB 35 separate placing booms are placing concrete inside the pillars.

Industrial construction
Cooling tower/chimney(in thermal power projects): The height demand for the cooling tower is above 100 m, so highly efficient and bigger capacity concrete pumps are required for pumping the special grade of high flow concrete and their valve mechanism should operate on the back concrete load. The wall thickness of the structure is less, so anchoring the concrete pipeline is one of the crucial parts. Separate placing booms are required for placing of concrete on the top.

- Sudheer Vathiyath