Wednesday 23 November 2016

The Jacker / Packer

The 'humpback' at Laverton bridge, due to its higher replacement deck, has been testing PWay minds these last few days. If the hump is too prevalent, it will hinder the correct stressing of the CWR, so it has to be smoothed at each end. The lift required was too much for the tamper, unless dozens of passes were made.

The tamper was out at Didbrook on the normal running line yesterday, and parked itself by the Toddington signal box at the end of the day. This position was to let out a new arrival yesterday afternoon, the 'Jacker / Packer'.  The what? Then read on.....

This miniature and less sophisticated tamper has been hired in to do the special lifts at Laverton. Its first day of operation was also used to train one of our own people, so that we could, if required, use it on a bare rental basis.

After quite a long wait, it eventually trundled into sight at Laverton bridge. It's not a racing car, OK, but it does rumble along steadily. The southern bridge approach has already had a first pass from the big tamper, and looks reasonably good.

Not so the northern end, where the trackbed is rather lower, and a considerable volume of extra ballast is needed to be able to lift the track to the required height. This was worked out beforehand and various datum points noted along the rail.

A gang of 8 had a go at manually raising the track, but did barely 10 yards in a day. It was really hard going, so the Jacker / Packer was hired in.

The 'lump' visible here is the height we need, so there is a lot more lifting required around it.

It didn't take very long to set the machine up. All you need to do is drive it to the site, and release the tines, which are secured (for travel) underneath.

Note the lifting hooks behind, which have already grabbed the rail in the picture.

A pair of hydraulic rams then pushes down, thus lifting the machine, which is clinging to the rails.

The height is determined by the operator, using sighting boards. The cant can be adjusted using a graduated spirit level inside, with each ram operated individually.

Once the height and inclination are satisfactory, the operator closes two double sets of tines around the chosen sleeper. It pushes the ballast underneath, but does not vibrate like its bigger brother. If you now retract the hydraulic ram, the track should stay up... if you have enough ballast.

You can see here that the lift was a high one, and that we indeed now need more ballast here,as the sleepers can be clearly seen emerging from the ballast bed.

In due course we will run another ballast train over this, followed by a final tamping from the big machine.

A good old-fashioned visual check along the top of the rails does no harm, and also ensures that we do not go to high. When tamping, you can go up, but you can't go down! Alas.

In this picture you can see the job that the Jacker / packer is doing. It has started at the far end of the hump, and is slowly working towards the camera, slowly decreasing the lifts as we get to the bridge (behind the camera) where zero lift is required. A sighting board has been placed at the end of the stretch to be lifted.

As we move backwards towards the bridge, Peter, prone, confirms the progress while Bob, on board the machine, makes sure the rams go down in the right place. Our trainee Martin, already an experienced plant operator, but not on this one yet,  looks on.

Here Martin is operating the machine, under the supervision of owner / trainer Bob.

It all went very well, it's not a complicated machine to learn.

Our conclusion was that the session went well, the machine did the job it was asked to do. It may well be useful elsewhere on the railway, if we keep it for a while.

Next, more ballast here, and the big tamper returns.

Back at Toddington, work was proceeding in the newly rewired goods shed on the Broadway station canopy. The big riveter has been tried out on half a dozen rivets, which are now in one of the fascia boards. What a lovely construction this is turning out to be. Just imagine the lofty construction above you, with a whole series of rivetted arches sweeping along above the platform side facade.

Back at Broadway, a customer came to collect 5 replica GWR platform lamp posts, cast specially for him in addition to those recently planted on platform 2. All profits go to the GWSR, so if you you want one or more for your railway or garden, get in touch via the company website.


  1. Lamp posts are turning into a nice little earner. They do look nice, even better with fancy paint work.

    1. Thanks, Gordon ;-)

      The posts will be decorated in light and dark stone. They were painting the platform 2 columns in light stone today and dark stone will follow on the raised surfaces, depending on dry weather of course.

  2. What a wonderful machine. So glad it's working out and that a 'hump back bridge' sign will not have to be a feature !?! I'm waiting with baited breath for signs of completed Broadway canopy sections, so I am also pleased to see the riveting progress. Also pleased that yo have a customer for GWR lamp posts. Regards to all, Paul.

  3. The lifted track will stay put with ballast underneath? You won't need to keep re-tamping or build a solid support underneath to run it off the bridge deck? Jim R

  4. How much are the lamp posts? then I will see if I can get this past her indoors! Great progress with ths bit of kit, will you be able to do a short video clip of it working? Also when is the next lot of ballast due? If I get the chance on Saturday i will try to see the rail head for myself. I am going to the Wareley show at the NEC on Saturday so I will try to divert with the helicopter (shareing the cost with 7 others, Cant afford my own!) if the weather is OK otherwise a long drive in the car!(Dont fancy the train as there are too many trackworks going on the route I would have to take!) Great work everyone!

    1. Hi Paul

      To talk about replica GWR lamp posts, send me an email at breva2011 (at)

      Dunno about ballast, it comes in to Stanton on demand, but is also used elsewhere on the railway. No doubt they will drop some at Laverton to fill the voids created by the J/P.

  5. anyone coming to the NEC M/R Warley show we have the GWR stand E14 and hope to see you .if you want to save and avoid NEC Car park fees , go to Hampton in Arden Station one stop south from NEC / Bham Int FREE Carparking +ains 26 mins past the hour all weekend via London Midland

    john mayell

  6. Excellent work Jo & Team! Those canopy bits and pieces are starting to look great and will be excellent when they all come together under a rebuilt Broadway station roof.

    Not to detract anything from the team, but is it worth getting in touch with GWR/Chiltern and it's contractors to see if there is anything worth left saving from the GWR Canopy at Oxford station? It shouldn't have long left to go now but some of it's still standing. Either way, I for one am certainly looking forward to the day when we see the first trains up on the rebuilt line to a rebuilt Broadway, a true credit to all!

  7. Impressed with Little Yellow Jack, and the amount of work it can do- and barely bigger than a Landrover.
    Couldn't help wondering- wouldn't it have been easier to re-grade the trackbed up to Laverton bridge, rather than have to invest in all that effort and ballast?
    Rosie the Riveter looks an impressive bit of kit, as well!

  8. On a point of information on the Laverton Bridge, the difference in height between the new concrete deck level and the original steel one was about 180mm. A ramp app. 100 Mtrs long was put in on either side of the bridge, and the extra ballast and laying was completely paid for by National Grid, who paid for the total Bridge re-decking work, back in 2009.

  9. Hi, could anyone tell me the contact details for hire of the Jacker Packer please? Thanks, Steve Vincent, email to.

  10. How much are the replica lamp posts, Jo? Can you do Midland ones as well (Berkeley)?