Blog Archive

Thursday, December 14, 2017

Carriage Project Part I - Calculations & Concepts



I think it’s safe to say we can skip the why’s and wherefores’! Anyone familiar with Puffing Billy will know that passenger numbers are through the roof and our little trains are struggling to cope with the ever-increasing demand. At the same time, as much as we try and dissuade them, our marketing department insist on jetting off to the next growing overseas market, building relationships with tour operators who send us yet more passengers!

Two years ago, the Rolling Stock Branch, looking ahead as always, published a paper which identifies the current capacity constraints, and when they occur. The report, put together by Rob Reed, a Puffing Billy fireman and engineering student on work experience, details the times when all rolling stock is utilised, and during those times, how often we reach full capacity, as well as various operational ideas to increase capacity without the availability of more carriages.


The remainder of the report involved calculations to try and ascertain the maximum practical carriage length, and how this compared with the existing carriages in terms of capacity, weight and cost. If you consider that every carriage must have two bogies, 2 sets of couplers & draft gear, and 1 Westinghouse combination brake unit, then if you are trying to keep the train weight down whilst maximising passenger accommodation, you would try to make your cars as long as possible.

The cost of all these parts in comparison to the total cost of a carriage is also considerable, so there are several potential benefits to an increased length.


At this point is should be mentioned that, whilst reducing weight is beneficial, losing too much can have a detrimental effect. The Nadal formula, or L/V ratio, relates the lateral force of the flange against the rail to the downward force exerted on the rail by the wheels. If these forces are not considered at the design stage, there may be a tendency for vehicles which are too light to climb the inner face of the rail and come off the track.

So, where did that leave us? The report was issued to management and the Board, with a recommendation that the any new rolling stock be of a standard 11 metre length, some 4 metres longer that the original VR carriages, and giving a seating capacity of 42 passengers.


Our existing wooden bodied NBH carriages weigh somewhere in the region of 5 tons, with a capacity of 28 people, giving a mass per person of 178 kg. An 11 metre carriage with a capacity of 42 passengers would give an approximate mass per person of only 177 kg, despite the change from timber to steel construction.

At this point we were asked to put come concept designs together, based on the previous steel-bodied NBH cars, open carriages being considered the most popular with our passengers. This we duly did, and feedback received was that 11 metres was thought too much of a jump in length from our existing rolling stock, and would look out of place within a consist.


Back to the drawing board – or 3D CAD software in this case – and the result was a 9-metre carriage, this being the same length as our existing extended NBH carriages, 51 & 52, with seating for 34. An NBHC variation was included, combining an NBH with a guards compartment and wheelchair accommodation.

Various options were put forward at the concept stage but not incorporated into the final design, including:
  • Two seating options, the first with longitudinal bench seats as per the existing cars, and the second with 2+1 transverse seating and end doors to allow for walk-through functionality. The walk-through option would allow for future inclusion of food and drink service on the trains, access to toilets, and maybe even a buffet or bar car. It was also considered advantageous to make access to seating easier, particularly for people with reduced mobility. 2 + 1 seating would negate the need for squeezing along the narrow gap in front of a bench seat already occupied with adults, kids, bags etc.
  • End windows, which you might have picked up from the images, were originally just added to the disabled access end of the proposed NBHC type carriages. It was envisaged that these combined guards/disabled access vehicles would operate with the guards compartment on the in-board end, creating the effect of an observation end, and hopefully a much-improved visual experience for our disabled visitors.
  • In a further iteration, and for consistency, these end windows were added to both ends of the NBH and NBHC type vehicles, with a view to increasing passenger security and safety. Whilst we can’t have a conductor in every carriage, guards and conductors must be as vigilant as possible, and these end windows would potentially allow staff to keep a better eye out along the train.


As part of the Rolling Stock Branch project control process, all groups and individuals considered to be stakeholders in the project were consulted, including the management team, Emerald Tourist Railway Board, Passenger Operations, Traffic Branch Committee, Puffing Billy Preservation Society Executive Committee, and the Heritage Advisory Committee.

Several consultation meetings collected much useful feedback which was taken into consideration as the concept design was firmed up into a final iteration. In particular, much discussion surrounded the layout of the guards compartments in the NBHC, seat layout and design, access and egress issues, and, most importantly, classification and numbering!

After many months of work, the Emerald Tourist Railway Board approved the detailed design, costing and manufacture of 12 new passenger carriages, 8 to be of the NBH type, and 4 to be of the NBHC type, all mounted on a standardised, light-weight 9 metre underframe and newly manufactured 'Fox' type bogies.

To be numbered 24 to 31, the new NBH carriages will weight approximately 6400 kg, and accommodate 34 passengers, giving a mass per passenger of about 188 kg.

The 4 new NBHC carriages will be numbered 1 to 4, and have an approximate mass of 6650 kg. With a capacity of 24 people, or 12 and 6 wheelchairs, this gives a mass per person of roughly 275 kg.


General Arrangement - NBH Class Carriage


Floor Plan - NBH Class Carriage


General Arrangement - NBHC Class Carriage

Floor Plan - NBHC Class Carriage

Part II - Coming Soon!

Friday, November 17, 2017

Garratt Happenings: The NG/G16 129 August Update

Work moves on apace with NG/G16 129, including the following tasks:

  • Removal of boiler from the cradle to enable final installation of all the steam, exhaust and water pipework, as well as insulating and cladding the boiler.

  • Superheaters and main steam pipes have been fitted in the smokebox (above and below).

  • Work on the sanding gear; sandboxes, air sand traps and pipework.

  • Overhaul of cylinder and linkage for the rocking grate, including manufacture of new components as required.

  • Refurbishment and manufacture of components for the lubrication system, including overhaul of the Wakefield Lubricator (above) and assessment of dividers, atomisers etc. for the lubrication lines (below).
  • Manufacture and fitting of blowdown valve linkage.
  • Riveting of the running boards to the boiler cradle, and grinding back of rivet heads.
  • The manufacture of pins and bushes for the valvegear continues, with many parts trial fitted to the engine units.
  • Installation of tank support timbers, engine unit footplates and lubricator mounting plates.
  • Final assembly of steam and exhaust pipework on the engine units, including steam expansion joints.
  • A custom-designed lifting bracket for the rear of the boiler has been fabricated and load tested, reducing the time and effort required to sling and balance the boiler when lifting.

Thursday, July 20, 2017

A Neat Space Saving Feature


One of the things we have an eternal struggle with at Puffing Billy is a lack of space, whether that be offices, workshops or just undercover storage in general. 


Nowhere is this more evident that the carriage workshop at Emerald; with barely enough accommodation for 3 carriages, this facility is responsible for the annual mechanical and body maintenance of all the railways rolling stock.


With a heavy maintenance schedule, it was thought desirable to improve the way components were stored before being refitted to the carriage or wagon. Bogies in particular take up a lot of space, particularly when they are complete with wheelsets.


This simple frame was developed as a means to stack bogies for storage.

Manufactured from profile cut steel plate, lengths of tube and threaded rod, the design is simple but effective, allowing pair of bogies to be stored in stacks, freeing up floor space for the staff working on maintenance.


Above, one of the frames assembled and ready for use, and below, two frames in use as intended, storing bogies.


The frames have even come in handy when transporting bogies between the workshops at Emerald and Belgrave!

216 NQR; The Finishing Touches


Hugh Markwick and the workshop volunteer team have now completed work on the restoration of 216 NQR. Above, 2 of the team pose in the sun at Emerald with the finished wagon.


The bodywork, drop doors, drawgear and fitting up of the air brake pipework all took place in the Belgrave workshop.




Once complete,  the wagon was transferred to the Emerald car shops where it was lifted for an undergear exam, after which it was passed for traffic.



After a final coat of paint, sign writer Colin Campbell visited Emerald to apply the finishing touches; historically accurate Victorian Railways style numbering and lettering, and a fantastic job he made of it.





The above series of photographs show the process of marking out, prior to applying the lettering.

The following video shows Colin applying the final layer of paint, all by hand - No stencils here!


216 NQR has been out and about recently, helping share the load on wood collection trains, and is a testimony to the hard work and dedication of the Rolling Stock branch volunteer team, and the staff who helped out along the way…..a job well done!

Wednesday, July 19, 2017

Scavenging The Last Remaining....


Mention has been made previously of the need to manufacture more bogies for our rolling stock. Many are now approaching the end of their useful life, with frames and axleboxes being condemned after a lifetime of wear and tear.


The new rolling stock project involves the manufacture of 12 new carriages, and therefore 24 bogies, onto which we have added a further 8 to ensure we do have spares available as old ones are progressively withdrawn from active duty.


This however is still some time away, and we needed a more immediate solution. With a critical shortage of serviceable axleboxes, attention soon turned to the bogies sitting under off-register rolling stock. These would be able to provide our immediate requirements, provided we could come up with a suitable substitute, which didn’t involve rolling stock on stack of sleepers littering the railway.


After sketching up a few ideas, the engineering office produced a concept for a quick, cheap and easy substitute axlebox, which would be perfectly adequate to keep our off-register rolling stock portable, whilst freeing up valuable Fox bogie axleboxes.



The design uses profile cut steel and nylon plates, with a minimum of machining, to replicate all the interfaces of the existing axlebox, including the horn slots, axle journal, and spring locating spigot. 

Two profile cut nylon plates are sandwiched between two steel plates to the same profile, and a hole to receive the axle journal bored through the middle.

Emergency Surgery For Thomas


During 2016, the decision was taken to trial moving the Day Out with Thomas event to Gembrook, starting with the spring season, thus inaugurating Gembrook as the railways new centre of special events.

Locomotives and rolling stock were transferred in the Down direction on a Friday evening, and back again on Sunday evening at the conclusion of the weekends shows. Peckett No. 1711, which usually masquerades as the cheeky blue tank engine, began to suffer from the extra mileage; overheating bearings on the rear axle being the problem.


Sadly Thomas’ arthritis continued to play up, despite the workshops continued efforts to cure it. At his lowest point, he was lifted onto a tilt tray and trucked from Belgrave to Gembrook, where he was only able to trundle around the yard and pose for photos with his many visiting admirers.


If dropping wheelsets out of a locomotive was an Olympic sport, the Belgrave workshop team would have it in the bag; the brake rigging, motion, valve gear and wheelsets were being removed and replaced 3 or 4 times in a week while measurements were taken and rectification work carried out.


The problem was bought under control so that the autumn season could be completed, at which point the decision was taken that Thomas would spend Christmas at Belgrave undergoing a ‘D’ exam.




On top of the usual tasks involved in this level of exam, the wheelsets were removed, and following detailed measurements, machining of the axleboxes and horns was carried out to rectify some misalignment which would have been a contributory factor to the overheating.


Coupled with a revision of the lubrication regime, the problem seems to have subsided for now, and the little blue engines performance during the Autumn 2017 Thomas events were much improved.



Above, Pistons and Crossheads have been cleaned and crack tested, and below, the Slidebars, Connecting rods and Coupling rods have all undergone the same treatment, and await reassembly to the locomotive.





After all parts of the motion had been cleaned, degreased and crack tested, they were given a fresh coat of red paint before refitting.


The opportunity was also taken to make some improvements to the spark arrestor (below), which was beginning to show signs of wear; the results of a hard life!



With everything cleaned, tested, painted and reassembled, 1711 was steamed for a test run back to Emerald. 

Following a successful run to Menzies Creek light engine, an NAL carriage (a dining car, originally from the Mount Lyell Railway in Tasmania) was coupled up, as it was destined to undergo maintenance at the Emerald Carriage Workshop.

The engine steamed well up the notorious Emerald bank, suffering no overheating issues, and with an improved lubrication regime, the Autumn Thomas season presented no further issues.


For the future, a CAPEX for an increased capacity mechanical lubricator has been approved, which will allow for forced lubrication of the axlebox crowns, reducing the chance of further hot-boxes being caused by a lack of sufficient lubrication.