Time allowed for loco exams and brake block change?

[w124bob]

I had first hand experience years ago of waiting for loco's to come off an A exam or a brake block change but can't recall the allocated hours, it was often the case that the actually time taken was less than the "book" time. I'm most interested in the A exam and brake block change time allowance, as these were often done at small F&I points whilst anything longer usually required a home depot visit. Obviously times varied depending on class, I also can't recall whether exams were mileage or engine hour based. 

[russ p]

Exams were on TOPS hours and some classes still are but more modern stuff is on different systems.

To block a loco obviously depends on  everything coming apart easily. Not sure how long BR allocated for A exams etc but I recall A exams been done in the running shed at Thornaby 

[roythebus]

As russ p says, it depends how easy all the bits come apart. BR had to allow for all but the most awkward bits to come off relatively easily, then adjust the linkages one the new blocks are on, then check they actually work when pressure is applied to the blocks via the brake cylinders.

 

[Davexoc]

Can't remember the book times, but an A exam doesn't take that long unless there a problems/reported faults.

 

Brake blocks is a different matter, class 47s had automatic adjusters which needed winding off and were a doddle, but a class 50 could involve removing all the split pins and linkages to move them back a hole to get the news blocks in, it would then need the reverse once the blocks were part worn.

I've seen a 47 come into 'The Factory' for blocks and be out again within 20 minutes. The new blocks would be laid out before it came in, having been sent over from the servicing shed, and the loco stopped in the right position.

[Rivercider]

Back in the 1980s when working in Bristol TOPS we would receive fax messages from Bath Road giving details of A Xams carried out in the Daily Shed. As I recall they generally showed the loco(s) stopped for one hour each.

B Xams etc and most other repairs carried out in the Main Shed, or Workshop, were input by someone on the maintenance side at Bath Road and not by us in Bristol TOPS.

 

cheers

[The Stationmaster]

A Exams for mainlne diesels were originally based on, I think, a 3 day interval assuming there was also Daily Inspection at a fuel point.  When loco maintenance went onto TOPs the exam intervals were based on real engine hours rather than assumed hours.

[slilley]

Funnily enough I am just reading a 1980 report into Class 45/1 availability and it lists the time that should be taken, excluding any repairs needed.

 

Exam      Interval        Labour Duration

A exam   55 hours      4 man hours

B exam  275 hours     10.3 man hours

C exam  825 hours      27.3 man hours

D exam 2475 hours    47.8 man hours

E exam 4950 hours     79.5 man hours

 

Hope this helps

 

Simon

[w124bob]

So a class 47 was about 1 hours work and 3 in the pub! I can remember seeing brake blocks laid out around a 47 at Burton on Trent F&I, one trick that the regular fitter did there was to try and find a fault. It would get them out an unpleasant job as it was a bit of wind tunnel at Burton, the other trick was to leave for the other shift ! The regular fitter and mate were brothers Jack(70 plus when they closed the depot) and George(66ish), the other shift was covered from Derby.

[Davexoc]

When quoting 4 man hours, that would be one hour each for two fitters, one electrical, one mechanical, then a fitter's mate and a labourer.

That gets all the checks done, oil sampled and all fluids topped up. Blocks are extra...

[HGR]

TOPS 'hours' were based on engine hours but with an applied conversion (fudge) factor, that varied over the years between 1.6 times to 1.8 times, reflecting experience gained at estimating the maintenance need compared to deterioration of equipment / component parts to achieve the desired reliability / availability figures.

 

The exam schedule with 55 'hour' baseline applied to the general common-or-garden mainline diesel loco classes. There were some exceptions where intensive use or arduous service conditions mandated a schedule with a shorter baseline. I seem to remember it was 39 hours for Deltics ?

 

Doesn't apply to AC electrics as these had their own schedule based on 'balanced work'. This has the content of the 'A' exam that must be done every time round, and a proportion of the work content of each of the other levels of exam. That way, each visit to the shops was expected to be of similar duration barring work arising, such as unplanned or unexpected defects being found. This strategy tended to be adopted for multiple units on intensive services.

 

When you look at diesel shunters, in the same way as wagons, these we considered worked to a calendar, not service hours. That being, days / weeks / months.

 

Simon : I do hope that means there's a Peak book in the pipeline to look forward to ?

 

[Rivercider]

1 hour ago, HGR said:

TOPS 'hours' were based on engine hours but with an applied conversion (fudge) factor, that varied over the years between 1.6 times to 1.8 times, reflecting experience gained at estimating the maintenance need compared to deterioration of equipment / component parts to achieve the desired reliability / availability figures.

 

The exam schedule with 55 'hour' baseline applied to the general common-or-garden mainline diesel loco classes. There were some exceptions where intensive use or arduous service conditions mandated a schedule with a shorter baseline. I seem to remember it was 39 hours for Deltics ?

 

 

Loco hours 'worked' on TOPS were not always accurate. A loco working on a timetabled mainline service for which a TOPS train schedule existed would accrue hours based on time input on departure from origin station, and time arriving at destination station. However a loco on local trip work might be actually working for several hours, but depending on how timely or accurate the reporting to the local TOPS office was perhaps only an hour might be reported. This was because the local trip moves were reported by a 'C7' yard transfer procedure, and the correct loco was not always input (indeed in the early days of TOPS the yard transfer procedure could update wagon details by using any 5 character loco number - even 00000)

 

cheers 

1 hour ago, HGR said: