Post by stanmorek on May 20, 2009 20:25:46 GMT
Permanent Way Institution Seminar
Practical Inspection & Maintenance of S&C
At Southbank University 29 April 2009
BULLHEAD S&C (Points & Crossings)
By Nick Kinman (Tube Lines Limited)
Introduction
This was one of four presentations made to the PWI on the inspection and maintenance of track junction work of notably bullhead rail on London Underground. The speaker was from Tube Lines and the term ‘S&C’ was used throughout in place of the more familiar ‘P&C’ LUL terminology. This was presumably to avoid causing confusion to an audience of mainly from main line rail.
Statistics
Tube Lines maintains 320km of London Underground track in various forms with 55% in deep level tube tunnels and the remainder in above ground sections.
Tube Lines are responsible for 257 S&C units on passenger running lines and 329 S&C units in depots. Of which 66% of S&C units consist of bullhead rail and presents a challenge for the future signal upgrades.
S&C Safety Inspections on London Underground
Track Patrols – Patrolmen on a twice weekly cycle will carry out S&C checks on their patrol routes. This is an overview of component condition and stretcher bar integrity.
Ultrasonic Inspection
districtdave.proboards.com/index.cgi?board=Signals&action=display&thread=1605
Track Recording Vehicle – The TRV will soon be replaced by the new Asset Inspection Train and features a laser based rail measurement system with electronic data analysis and an improved accuracy of within 1 metre. The current TRV relies on a paper based reporting system and detects faults with an accuracy of within 10 metres.
PM3 Inspections - Track manager quality inspection every 4 weeks.
PM4 Inspections - Are carried out by safety critical licensed inspectors. This involves a detailed examination of all track components of junction work. Items include component wear, entry and exit components, 3rd and 4th rail, ballast condition and reporting on signal equipment condition. PM4 inspection frequency can be 4, 8 or 12 weekly depending on a risk assessment as allowed in LUL standard 1-158 Cl 3.6.2.3. The risk assessment criteria takes into account of the location, track curvature, usage, switch type, derailment history, etc.
The inspection process identifies maintenance works which is planned and prioritised using the electronic asset management tool Maximo. Metronet uses a similar system known as Ellipse. However, safety critical Level 3 faults require immediate minimum actions as specified in LU standards.
History of S&C Maintenance on London Underground
During the early 1980s there was an annualised budget for regular track renewal and maintenance where funding was significantly higher than current levels. By the mid 1980s there was evidence of worn switches and a more robust S&C inspection regime was introduced and point care teams were also trialled.
In the 1990s, track access for maintenance work was still available during the day and carried out between trains. However, due to the introduction of various health and safety legislation, e.g. Electricity at Work Regulations, maintenance is now carried out during engineering hours. Presently day patrolmen are limited to performing essential light maintenance such as replacing bolts in fish plates.
During this period, there was a lack of investment and there was no recognised method of S&C ballasting. Compared to S&C maintenance on the main line network, LU lacks mechanised S&C tamping and relies on hand ‘kango’ packing with occasional hand held stone blowing. From the PPP Contract Tube Lines have inherited an S&C tamper loaned from GBRf. However, the tamper can only be worked in limited areas due to structure gauge clearances issues.
Developments in S&C
There are limited renewal opportunities on LU to rationalise layouts and flat bottom rail replacement is carried out piecemeal. Also the use of bullhead has long been favoured due to being lighter then flat bottom and easier to handle and the historical knowledge of LU track gangs. Existing layouts with limited length of turnouts have been optimised for tube tunnel design.
LU developed bullhead semi-welded crossings in 1995 at their Lillie Bridge workshop. These are fabricated by clamping together two machined rails and are tack welded to form the nose and then completed with infill weld by an automatic welding machine. These crossing components have suffered a history of fatigue cracks in particular at the A-B chair location and the design needs to be reviewed.
A development by Tube Lines is the introduction of the tube train based Disab vacuum system imported from Sweden. Its applications include ballast renewal and drainage catch pit cleaning. Pulled by two battery locomotives the train consists of a vacuum unit to suck up old ballast and a ballast filtration and cleaning unit. Also included is a ballast wagon with train mounted crane with bucket attachment. It is capable of removing 15 cubic metres of ballast an hour and is only limited by the size of the ballast hopper (18.5 tonnes) on the train. At a hire cost of £11,000 per shift it can renew 4 beds in 20 minutes. A track gang of 10 men can replace 5 beds in a shift.
Practical Inspection & Maintenance of S&C
At Southbank University 29 April 2009
BULLHEAD S&C (Points & Crossings)
By Nick Kinman (Tube Lines Limited)
Introduction
This was one of four presentations made to the PWI on the inspection and maintenance of track junction work of notably bullhead rail on London Underground. The speaker was from Tube Lines and the term ‘S&C’ was used throughout in place of the more familiar ‘P&C’ LUL terminology. This was presumably to avoid causing confusion to an audience of mainly from main line rail.
Statistics
Tube Lines maintains 320km of London Underground track in various forms with 55% in deep level tube tunnels and the remainder in above ground sections.
Tube Lines are responsible for 257 S&C units on passenger running lines and 329 S&C units in depots. Of which 66% of S&C units consist of bullhead rail and presents a challenge for the future signal upgrades.
S&C Safety Inspections on London Underground
Track Patrols – Patrolmen on a twice weekly cycle will carry out S&C checks on their patrol routes. This is an overview of component condition and stretcher bar integrity.
Ultrasonic Inspection
districtdave.proboards.com/index.cgi?board=Signals&action=display&thread=1605
Track Recording Vehicle – The TRV will soon be replaced by the new Asset Inspection Train and features a laser based rail measurement system with electronic data analysis and an improved accuracy of within 1 metre. The current TRV relies on a paper based reporting system and detects faults with an accuracy of within 10 metres.
PM3 Inspections - Track manager quality inspection every 4 weeks.
PM4 Inspections - Are carried out by safety critical licensed inspectors. This involves a detailed examination of all track components of junction work. Items include component wear, entry and exit components, 3rd and 4th rail, ballast condition and reporting on signal equipment condition. PM4 inspection frequency can be 4, 8 or 12 weekly depending on a risk assessment as allowed in LUL standard 1-158 Cl 3.6.2.3. The risk assessment criteria takes into account of the location, track curvature, usage, switch type, derailment history, etc.
The inspection process identifies maintenance works which is planned and prioritised using the electronic asset management tool Maximo. Metronet uses a similar system known as Ellipse. However, safety critical Level 3 faults require immediate minimum actions as specified in LU standards.
History of S&C Maintenance on London Underground
During the early 1980s there was an annualised budget for regular track renewal and maintenance where funding was significantly higher than current levels. By the mid 1980s there was evidence of worn switches and a more robust S&C inspection regime was introduced and point care teams were also trialled.
In the 1990s, track access for maintenance work was still available during the day and carried out between trains. However, due to the introduction of various health and safety legislation, e.g. Electricity at Work Regulations, maintenance is now carried out during engineering hours. Presently day patrolmen are limited to performing essential light maintenance such as replacing bolts in fish plates.
During this period, there was a lack of investment and there was no recognised method of S&C ballasting. Compared to S&C maintenance on the main line network, LU lacks mechanised S&C tamping and relies on hand ‘kango’ packing with occasional hand held stone blowing. From the PPP Contract Tube Lines have inherited an S&C tamper loaned from GBRf. However, the tamper can only be worked in limited areas due to structure gauge clearances issues.
Developments in S&C
There are limited renewal opportunities on LU to rationalise layouts and flat bottom rail replacement is carried out piecemeal. Also the use of bullhead has long been favoured due to being lighter then flat bottom and easier to handle and the historical knowledge of LU track gangs. Existing layouts with limited length of turnouts have been optimised for tube tunnel design.
LU developed bullhead semi-welded crossings in 1995 at their Lillie Bridge workshop. These are fabricated by clamping together two machined rails and are tack welded to form the nose and then completed with infill weld by an automatic welding machine. These crossing components have suffered a history of fatigue cracks in particular at the A-B chair location and the design needs to be reviewed.
A development by Tube Lines is the introduction of the tube train based Disab vacuum system imported from Sweden. Its applications include ballast renewal and drainage catch pit cleaning. Pulled by two battery locomotives the train consists of a vacuum unit to suck up old ballast and a ballast filtration and cleaning unit. Also included is a ballast wagon with train mounted crane with bucket attachment. It is capable of removing 15 cubic metres of ballast an hour and is only limited by the size of the ballast hopper (18.5 tonnes) on the train. At a hire cost of £11,000 per shift it can renew 4 beds in 20 minutes. A track gang of 10 men can replace 5 beds in a shift.
