Baldwin "Lyn" new build.

It is an intesting topic, but I can see a few issues.

1) The steps in the tread could cause the creation of stress-raisers that can lead to cracks in the tyre - the drawings do not show any radii on the interfaces, however depending on the geometry and stresses in the tyre even this may not resolve it (as with with all shafts and axles the highest stressed area are the grains on the surface and at the transition radii where the diameter changes - the stress analysis of such items is a highly skilled area). Based on the old BR MT162, the limits of indentation of treads (from damage or wear) varies depending on the condition of the edges: Scores (with sharp edges) on a wheel tread are permitted only to a depth of 1mm and Grooves (with blended radius) are only permitted to a maximum depth of 2mm (same limits as hollow wear).

Below are are the standards that apply to wheelsets permitted to run on Network Rail (from the RSSB website) GMRT2466 and GM/GN2497 As can be seen in figure 10 of GM/RT2466 the proposed profile is inserting new detail into an area of the tyre that is already prone to crack developement on conventional profiles.

http://www.rgsonline.co.uk/Railway_...ck/Railway Group Standards/GMRT2466 Iss 3.pdf
http://www.rgsonline.co.uk/Railway_Group_Standards/Rolling Stock/Guidance Notes/GMGN2497 Iss 1.pdf

2) There will be issues with tread rollover - This phenomenon effects all wheelsets and develops during service by local plastic deformation of the wheel tread. Normally a burr of extruded material forms on the edge of the outer rim side of the wheel and if left to grow too large can cause stress raisers leading to cracks. In the case of this profile the developement of rollover would be difficult to predict but the step and the groove appear vulnerable.

3) The shape of the profile could lead to a reduction of area for brake block contact and therefore could effect the performance of your friction brakes.

I am sure you are already aware that the challenge facing the reponsible engineer of your railway is that you are introducing a novel design onto the most safety critical item on a rail vehicle (wheelset), and a comprehensive risk assessment of how the profile is safely introduced and initially tested in service is essential. I suggest you will need to set some conservative wear limits to begin with and very closely monitor the wear of the wheel tread in service. Bare in mind that it will be almost impossible to predict how this new profile will wear in service, and this means that it will be difficult to brief people to identify what visible signs of distress should be reported. It cannot be presumed it would look like the defects on existing wheel profile.

Kind regards,
Gareth

(Co-developer of the hybrid "P10-RD9" profile used on certain class 66 locos)

 

Hi Gareth, I am no expert on any of this, but I do try to follow what is going on, While I agree with you that running at Mainline speeds with the centrifugal forces on the wheels which come at those speeds would not the lower line speed of the L&B have as much to play in this design?

I have to admit to being a Porta fan and I like a lot of what he was trying to do, some of his work is so basic by today's standard it makes me wonder why some of his idea's have not been put into operation before now by some of the other heritage railways two come to mind one better steam circuits and better insulation, I know bright copper looks good, but think how much heat / energy is being lost along the external walls of these pipes of a steam loco.

 

In the grand scheme of things, not much! Steam engines are very inefficent, a little bit of saving on a pipe here and there isn't going to make much difference on anything short of cylinder supply and exhaust pipes where dryness of the steam matters. Heritage Railways are about showing how things once were, why would they shield up the classic signs of victorian design such as magnificent copper work?

 

You're confusing a heritage/preserved artefact with a representative new-build, and also moving slightly off-topic. Such new-builds allow modern technology to be incorporated into an existing design where possible, seen all the time on cars with new features being built in (how long has the Golf been around now?). If building things to original works patterns is your thing then fair enough, but in the semi-commercial environment of most heritage railways of trying to be most efficient as possible then it makes sense to try and incorporate modern techniques. Not just in the case of HAWP, but also perhaps modifying the bearing surfaces for the use of roller elements lubricated by grease.

Would Kerr Stuart (for example) still be using split-cast axleboxes today if they were still building Wrens for Contractor's or industrial use? Probably not, the price and economy of roller-bearings (and even large take-up units) is such that they're much easier to use.

Like lynbarn I too am a fan of Porta, and have seen the effects first hand of GPCS on the locomotives ath te Kirklees Light Railway, and it makes me wonder how much longer mainline and industrial steam - of all sizes - would have lasted had British builders kept up with steam developments around the world and embraced them properly as in other countries. Heck it was only with Riddles' Standards that roller bearings became anywhere near the norm, and that was mid-50's when the coffin was already being nailed.

I take in the concerns of Gareth wrt HAWP, and can see where he is coming from. However there is the point raised by lynbarn of the speeds involved with todays' mainline stock which is entirely valid. I suppose the best answer would be to see how FCAF have got on with HAWP now they've had chance to establish its benefits over time.

Aside from HAWP, are there any plans in the UK of employing Steam-jet Rail Cleaning as also described on the HAWP page linked above?

Cheers,

Dom

 

Having taken a quick look through the thread, following the description "High adhesion Wheel profile" Umm , My first reaction was Umm.

Question was what were they going to do to the tyre tread to get more traction at the interface which is a narrow line. Then looking at the sketch, Um the modification to the outer edge of the tread is miles from the contact point between rail and wheel.
Mr Porta was tasked with a contamination issue on a highly used section of trackwork with bad oil and grease contamination, from the rolling stock and traction units.

Not with making a steam engine grip better.

The wheel profile is not an improved traction item , more a groove just in from the outer edge where apart from transitioning over Switches the tyre never touches the rail.

The groove is intended to stop oil and grease creep along a diameter and getting to the contact point.

I fail to see what point this modification would be on the wheels of Lyn used on the L&B where contamination of the rail head with oil and grease is not an issue.

In fact some lubrication is preferable and to some extent needed on the L&B because of its toiling curves and reverse curves.

No lubricant and curves, cause issues if the wheel cone angle is not matched to the extent of the curves and the curves super elevation at route speed, (in both directions of travel) and then the main drivers don't ride the right gauge line whilst negotiating the curve, under traction or braking.

I am not aware that the L&B has done much on Superelevation - V- Running speeds on their line and got the track line of the wheel sets correctly possitioned.

Not getting that detail right is more likely to cause loss of traction or adhesion when operating

In this case I put the view that this mod to the wheel tread is of no use at all, on this loco.

In this application it is possible a hollow radius profile comming away from the flange root radii would give better riding and best adhesion properties, on the rail head currently in use on the L&B.

Regards The Engineer

 

Lynformation 5 is now online. Many new items now ready! http://www.762club.com/762lynformation.php

 

I just visited the website for the first time in a couple of years. I must admit I was stunned at the thoroughness of the design process. Will this be the first ever steam locomotive designed anywhere in the world completely on a computer ? I must have spent an hour just lapping up the solidworks drawings on the designers own web page. The moving film simulation of the motion was brilliant. I wonder what the great loco designers of old would have made of the tools that we have now to ease the design process ? One skilled man doing what a drawing office of 20 would have done in the past.

http://www.machineconcepts.co.uk/baldwin242/baldwin2.htm

Best of luck to the project. It certainly deserves more attention than it is getting.

 

Probably the first using a 3D package like solidworks but I recall it being said that the FR's Taliesin was designed on a 2D package. I am sure somebody can confirm, but of course I could be wrong. I hasten to add that it is only a tool, the skills of the draughsman who produced it should recieve just as much applause as his Victorian predecessors.

Some live steam model makers such as Roundhouse in Doncaster have been using 3D packages for years, though.

 

Is there any up to date information on this project. The Lyn News page was last updated on January 6th. Previously it printed monthly updates.

 

Check out
http://www.machineconcepts.co.uk/baldwin242/baldwin3.htm
This is updated more often than the main page - all utterly fabulous stuff!

 

All is explained! There have been webhost difficulties that have limited the webmaster's access to the site. But new posts will arrive over the next few days. See new entry on the problem: http://www.762club.com/762news.php

 

Many thanks for the update on behalf of all your avid followers.

 

The latest (February's) LYNformation 25 is now up, and 26 will follow in a week or so! thanks all for your patience and interest in the LYN project!

 

All those wishing to see Lyn finished, and who have not yet contributed to the project, please go to the 762 club website and sponsor a part or take out a membership! There are parts as cheap as a few quid (see 'All piped up' appeal) to several thousand! Sponsor some paint for the final painting for around 50 quid, or take out a membership for 762 pounds!
Every little helps, as they say
www.762club.com

 

Why is the paint so expensive ?

 

Because it is special paint needed for steam Locos that get very hot and then cold again. It's not just house paint

 

Very exciting to observe this project as it reaches it's conclusion. Though I'm curious, once Lyn is complete do they plan on testing it out on the FR first for a time?

 

I have heard that the WHR is a possibility.

 

I would have the FR would be more suitable a place to put Lyn through it's paces, though truth be told it could be either since to certain extent they could be considered one and the same.