The Collapse of Ronan Point

Introduction The purpose of this paper is to consider the perceived failures associated with the famous collapse of Ronan Point on 16 May, 1968. Following a gas explosion, an entire corner of the 22 storey tower block in East London collapsed, killing 4 people and injuring 17. In order to analyse the failures that occurred, the paper will firstly look at the history of the building, its design and construction, before looking at the collapse itself and the perceived failures that were identified after the event. The building was named after the chairman of the housing committee of the relevant London Borough, Newham, and was one of many tower blocks built during the 1960s in a budget-driven and affordable way to deal with the growing demand for affordable housing in the region (Levy and Salvadori 1992). The very ethos of this affordable housing and the use of cheaper materials and cheaper construction approaches is arguably one of the first and fundamental contributory factors to the disaster (Griffiths et al 1968). Design and Construction The actual design and construction of the building was mooted as far back as the end of World War II, when much of the housing available in the London region was destroyed as a result of the war and there was a rapid demand for a large amount of housing. Other factors such as a lack of skilled labourers, as well as the changing housing policy which enabled multi-stories to be established, created a demand for the design and construction of buildings such as the one in question here. A prefabricated construction technique was used which involved the creation of much of the high-rise building which was then transported to the area for final construction (Cagley, 2003). The actual construction approach that was used here was that of the Larsen-Nielsen system which was composed of factory-built, precast concrete components designed to minimise on-site construction work. Walls, floors and stairways are all precast. â€Å"All units, installed one-story high are load bearing† (ENR, 1968 at p.54). Although this system was tried and tested, the approach was not designed to be used in a building of more than 6 storeys high. However, the building of this tower block was 22 storeys high and there was no recognition, at the construction phase, that this could potentially jeopardise the validity of the construction technique. The basic construction approach involved a precast concrete structure frame, with each floor of the multi-storey building being supported by the load-bearing walls directly beneath each other, floor upon floor (Bignell et al 1977). Collapse The collapse itself happened at 5:45 am in the morning when the tenant of one of the apartments on the 18th floor lit a match, unbeknownst that there had been a gas leak overnight. By lighting the match, an explosion took place and this ended up damaging the load-bearing wall which was present on the 18th floor and was acting as the only support for the corner of the 19th floor. When the corner of the 19th floor collapsed, this had the effect of the 20th floor collapsing. Once the floors above had already collapsed the pressure on the floors became unbearable and the domino effect continued downward, destroying the entire corner of the building (Delatte, 2009). The way in which the collapse took place meant that, essentially, it destroyed a portion of the living room all the way down the building, but left the bedrooms intact in most cases, with the exception of floors 17 to 22 the room which were in the immediate vicinity of the explosion. It was on these floors that all of the fata lities happened and due to the fact that the explosion had taken place early in the morning, the majority of the individuals who were in their bedrooms were unaffected (Delatte, 2009). Perceived Failures When looking at the perceived failures and causes of failure, it can be seen that the analysis is largely split into two distinct areas: first, considering the immediate cause of failure; the second looking at the fundamental flaws in the design and construction of the building that allowed such a dramatic reaction to the immediate event (Griffiths et al 1968). The actual investigation into the event which took place involved a government panel which was formed in order to look at the causes of failure and to consider whether or not there were other buildings which potentially could suffer from a similar eventuality, in the future. As stated previously, the construction approach taken for Ronan Point was replicated in many other buildings, with eight other exact replicas in occupation. Therefore, establishing the reason for the collapse is crucially important (Pearson and Delatte, 2003) One of the key factors that took contributed in the immediate event itself was found to be a substandard connection used in order to connect the gas stove in the relevant apartment. Whilst this meant that the gas leak had presented itself in a way that would not have been likely, had they used a different connection, as well as having the incorrect connection, it was found that over tightening had occurred during installation. This probably weakened the connection and allowed gas to leak out. Despite this, the evidence gathered suggested that the explosion itself was not substantial, as there was no permanent damage to the hearing of the individual in the apartment. This suggests that relatively little pressure was involved, although there was sufficient pressure to move the external walls of the building and to create a progressive collapse within the building (Levy and Salvadori, 1992). Broadly speaking, the progressive collapse is thought to have occurred due to the fact that there was a lack of alternate load paths available and there was no support for the structural frame available on the higher floors (Wearne, 2000). This meant that when there was an explosion on level 18, this took out the only support so that the floors above level 18 failed and this placed excessive pressure on the lower floors, until it ultimately collapse to ground level. Perceived failures, can be split into two distinct categories, the first being the cause of the explosion itself; the second looking at the repercussions of the explosion, which were extensive, given the magnitude of the explosion, which was relatively low. Procedure and Project Management Unsurprisingly, as a result of the collapse here, building codes, guidelines and regulations were advised not only in the United Kingdom, but across the globe. The building regulations, changed in 1970, state that any building with more than four storeys needs to have a design structure in place that would resist a progressive collapse of this nature (Pearson and Delatte, 2005, pp. 175). Apart from the construction mechanisms themselves, there were also concerns that failures had occurred in the project management, as well as failures to check procedures. The gaps between the floors and in the walls meant that the building had not been established in a way that was part of the original design and planning. In addition to the actual failure in the design of the property, concerns were also raised in the report in relation to the need for quality control of the construction processes taking place. For example, it was proven that during the construction, certain design factors had been ignored, with unfilled gaps between the floors and walls, throughout the premises, which meant that the building had little in the way of separation between the flats. Furthermore, in high rise buildings of this type, a relatively narrow staircase is acceptable, as there is thought to be enough fire protection between the floors. In the absence of this fire protection, narrow staircases w ould be unacceptable, in the event of a fire or explosion of this nature. Key Failures The analysis above indicates that there are several failures which together created the dramatic collapse at Ronan Point. These are: social pressures on the construction company to establish a large amount of housing accommodation, rapidly and cheaply; the use of constructions not aimed at high storey buildings of this nature; failures to put in place methods whereby there was no secondary support structure in place, in the event of a failure with any of the load-bearing walls; failures with the processes being followed, which resulted in the wrong processes being followed in the connection of the gas pipes, as well as other omissions during the construction process, with the failure to follow the design provided. It can be seen, that the project management would have, at least in part, dealt with many of these failures and would have either prevented the explosion, in the first place, or would have seriously reduced the impact of the explosion, once it did take place. The crucial factor in this analysis is that the explosion itself was relatively minor, yet the repercussions were large and it is this chain of events that requires attention when it comes to better project management, in the future. Recommendations for Better Project Management Certain failures took place at the design phase, when the design construction of the premises was selected, yet was not entirely suitable for a 22 storey building. This was arguably the first and crucial failure which could have been avoided with further research into the limitations of this design. However, the main focus of the recommendations presented here is in relation to the project management process, from the point at which the design was presented for the construction, to the point at which the building was completed (Pearson and Delatte, 2005). At the outset, when the project team came together, there was an opportunity to run scenarios and to check the validity of the chosen construction, given the design that were being presented and the need to establish a 22 storey building. By running these types of scenarios, it is likely that it would become apparent that the chosen construction design was simply inappropriate. Even without this element of the project management being undertaken and risk assessments being carried out, the next stage of the project management should have involved a strong quality control check for every aspect of the work. The fundamental design of the building was proven to be flawed; however, there were also errors during the actual construction phase, for example the use of the wrong connections when it came to the gas pipes installed. Although this, in itself, did not lead to the catastrophic collapse of part of the building, it did create a minor gas explosion which started the chain of events. Quality control processes at every phase of construction and fitting would have potentially prevented the chain of events from emerging, in the first place (Shepherd and Frost, 1995). Next Steps and Conclusions Bearing this in mind, there are several proposed changes and next steps which could be taken to prevent a similar failure happening in the future. Firstly, although the design used was accepted during this era, it was known that it would simply not be appropriate for the type of building which was being planned. This should have been noted, at the outset, with additional safety structures then planed so as to prevent this type of progressive collapse from taking place. Secondly, worst-case scenarios should be run, at the outset, to enable the project managers to ascertain whether any weaknesses existed. Moreover, although the rest of collapse in this case resulted in the building being destroyed, it was also not able to withstand strong winds and this also, ultimately, could have resulted in the building becoming uninhabitable. By running scenarios, such as high winds or explosion, these issues would have been highlighted and changes in the design could have been incorporated, from the outset (Pearson and Delatte 2003). Finally, quality control during the construction process was also not suitable. This should have been done with much greater consistency, to ensure that the smaller processes, such as the fitting of connections, was carried out to an appropriate standard, thus preventing the minor incident that ultimately led to the overall disaster. By following these clear project management approaches and ensuring that an individual was put in place, in order to manage quality and control, as well as any variables in this area, the collapse of the building could have been avoided, or at least the cause of the collapse mitigated against, so as not to cause loss of life and injury. References Bignell, V., Peters, J., and Pym, C. (1977). Catastrophic failures. Open University Press, Milton Keynes, New York. Cagley, J. R. (2003, April). The design professional’s concerns regarding progressive collapse design. Building Sciences, 27, 4-6. Delatte, N. J. (2009). Beyond failure: Forensic case studies for civil engineers. American Society of Civil Engineers (ASCE), Reston, Virginia, 97-106. Engineering News Record (ENR). (1968). â€Å"Systems built apartment collapse.† ENR, May 23, 1968, 54. Griffiths, H., Pugsley, A. G., and Saunders, O. (1968). Report of the inquiry into the collapse of flats at Ronan Point, Canning Town. Her Majesty’s Stationery Office, London. Levy, M., and Salvadori, M. (1992). Why buildings fall down: How structures fail. W.W. Norton, New York, 76-83. Pearson, C., and Delatte, N. (2003). Lessons from the Progressive Collapse of the Ronan Point Apartment Tower. In Forensic Engineering, Proceedings of the Third Congress, edited by Paul A. Bosela, Norbert J. Dellate, and Kevin L. Rens, ASCE, Reston, VA., pp. 190-200. Pearson, C.,and Delatte, N. J. (2005) Ronan Point Apartment Tower Collapse and Its Effect on Building Codes. J. Perf. of Constr. Fac., 19(2), 172-177. Shepherd, R., and Frost, J. D. (1995). Failures in Civil Engineering: Structural, Foundation, and Geoenvironmental Case Studies, ASCE, New York. Wearne, P. (2000). Collapse: When Buildings Fall Down, TV Books, L.L.C., New York, 137-156.