DEGRADED MODES OF OPERATION: ANTECEDENTS FOR RAILWAY ACCIDENTS Mr M MATHEBULA & Dr PN SOPAZI

IMPORTANCE OF THIS TOPIC TECHNOLOGY CHANGES (A) OLD AND NEW BEHAVIOUR AND ATTITUDE CHANGES (B)COMPLIANCE, PERFORMANCE AND SAFETY)

PRIMITIVE RAILWAY SYSTEMS Advent of railways in 1820s ‘Killer application’ Utility took priority over safety Wagons were drawn by horses No signalling system to control train movement Normal operations

UK Railway Group Standard (2007) Normal operations – describes the way in which the railway system was designed to operate; Abnormal operations – describes extreme loading on the part of the railway system, severe weather, or delay to train service; Degraded operations – describes when part of the system operates in a restricted manner, for example, signal failure

UK Railway Group Standard (2007) Emergency situations describes unforeseen or unplanned event which is life threatening or extreme loss implications and requires immediate attention, for example a fire or an obstruction on a line , a tsunami or an earthquake.

Degraded modes of operations indicators Staff shortage Limited secondary resources Limited experience resources Legacy equipment Intermittent failures Concurrent breakdowns

What leads to a degraded mode of operations The production of culture The culture of production Structural secrecy

The Space Shuttle Changer Disaster 1974-Morton-Thiokol awarded contract to build solid rocket boosters 1976-NASA accepts Morton-Thiokol’s (The designer’s) booster design 1977-Morton-Thiokol (The designer) discovers joint rotation problem. November 1981-O-ring erosion discovered after second shuttle flight January 24, 1985 – shuttle flight that exhibited the worst O-ring blow-by.

The Space Shuttle Changer Disaster July 1985-Thiokol orders new steel billets for new field joint design. August 19, 1985-NASA level 1 management briefed on booster problems. January 24, 1985-Thiokol orders new steel billets for new field joint design. August 19, 1986- night teleconference to discuss effects of cold temperature on boosters performance January 28, 1986 –Challenger explodes 72 seconds after take off

Challenger Inquiry: Structural causes Budgets cuts and compromises A widening gap between NASA goals and the means to achieve them Flawed decision making processes Substantial reduced work forces Managers overriding concerns and warnings In short: production pressures and managerial wrongdoing

Australia: Glenbrook accident 7 people were killed and 51 injured when an inter-urban train collided with the Indian Pacific in the Blue Mountain suburb in 1999. The pressure that was placed on train drivers to meet the timetable deadlines led to drivers to operate trains without functioning radios or with defective brakes.

New Zealand: Waipahi train collision Train 939 collided with Train 919. The train driver of Train 919 was fatally injured and train driver was seriously injured. Causal factors included one train driver misunderstanding of his track warrant limit There was recognition at all levels of Tranz Rail staff that there were recurring occasions when points for the opposing train to enter the loop were not set correctly.

United Kingdom The Ladbroke accident with 31 people being killed and more than 520 injured. The accident could have been prevented by an Automatic Train Protection system. Problems in training did not create the degraded modes of operation. However lack of knowledge and skills may undermine drivers’ attempts to cope with failures associated with degraded mode of operation.

How do you keep out of the pit? Risk assessment Contingency plans Spare personnel Fully functioning equipment Incident investigation and learning Safety maturity Training Risk awareness Experienced personnel

RECOMMENDATIONS CONCLUSION

Conclusion Degraded modes of operation…occur when staff continue to maintain levels of service when elements of the underlying technical infrastructure are unavailable. Degraded modes of operation occur when members of staff find ways of working around failures in the underlying technical infrastructure. http://www.skybrary.aero/index.php/Degraded_Modes_of_Operation (May 2016)

Conclusion It can therefore be concluded that; Organisations should desist from the normalisation of deviance because such deviation could lead to disasters. Organisations should not allow a degraded mode of operations to be a permanent state (i. e. attempts should be made to roll operations uphill into normal operations. THANK YOU BY: MR M MATHEBULA (RSR) AND DR PN SOPAZI (RSR)