How is this cross head/slide bar made up?

[jon price]

I'm trying (and failing) to understand how this crosshead on a Manning Wardle loco could be modelled. Any suggestions (preferably with simple diagrams)?

no9 b.JPG

photo courtesy of Flintshire Archive

[Knuckles]

I'm no expert on it and probably about to type rubbish but isn't it locked in the slidebars by a notch?

Maybe if you double up the slidebars width ways you can lock it in?

[John Fitton]

Jon,

Is it possible the slide bars are actually grooved

https://www.facebook.com/Manning.Wardle ... 271851895/

Seems like lower bar is, in this photo.

JF

[Alan Turner]

You can just make out the raised guide way in this enlargement.

no9 lg.jpg

regards

Alan

[jon price]

Thanks for all this input. I think a grooved slidebar that works is going to be well beyond my capability. Maybe slotted would be possible.

[garethashenden]

Thanks for all this input. I think a grooved slidebar that works is going to be well beyond my capability. Maybe slotted would be possible.

How about U section brass? Something like this http://www.eileensemporium.com/index.ph ... 4&Itemid=9 or this http://modelshop.co.uk/Shop/Strip-Shape ... el/ITM5599 ?

[David B]

I would be inclined to solder a piece of very small square section nickel silver along the middle of the rubbing surface of the slidebar. Eileens have some 0.65mm square. This would recreate what seems to be in the picture. You should then be able to make a corresponding groove in the crosshead.

[John Palmer]

I think I would go about this by fabricating 3-ply slidebars, with the middle lamination standing proud to represent the land that guides the crosshead. One advantage of this approach is that you would automatically attain accurate alignment of the guiding land. Your next problem is to form a fairly close fitting slot centrally in the crosshead slides...

I assume this arrangement was applied to both top and bottom slidebars in order to ensure adequate guidance of the crosshead/piston rod assembly and thereby minimise wear to the gland packing. The arrangement seems not to have caught on and I wonder whether this was because it complicated installation and maintenance of the white metal/bronze crosshead inserts.

[David B]

I think I would go about this by fabricating 3-ply slidebars, with the middle lamination standing proud to represent the land that guides the crosshead. One advantage of this approach is that you would automatically attain accurate alignment of the guiding land. Your next problem is to form a fairly close fitting slot centrally in the crosshead slides...

Good thinking, John. I agree - this would be a better solution than mine and would make a finer tongue. Making the groove in the crosshead will be more difficult to fashion but not insurmountable.

[Knuckles]

What if you solderd on a .3mm rod on the top of the slide bar and then file it to shape thinning the sides?

[essdee]

Gents,

This photo intrigued me from the start; I have never seen such an arrangement before. I have just recalled that I have a Pictorial History of Manning Wardle locos of all types, by John E. Simpson, and a trawl through this failed to reveal any further examples.

Proves nothing, on its own - I am open to seeing further examples if they can be found!

However, after studying the photo closely, I distinctly smelt rat. See how the following strikes you.....

1) Light reflected from/shadowed by convex surfaces demonstrates that the centre of the crosshead, with the little end pin, and therefore the piston rod, lie behind the apparent 'slot' within which the crosshead appears to move. This would be extremely unusual, and undesirable in engineering terms, surely? It would place the piston rod centreline on, or towards, the further 'flange' of the apparent channel section slidebar.

2) Now look at the motion bracket, and the nut underneath it which secures the lower slidebar. Again, the shadows and perspective suggest that the fixing stud on the lower slidebar is set towards its rear edge; again, rather unusual?

My strong suspicion is that we are looking at a conventional crossshead/slidebar arrangement, with additional strips fixed in front of the upper and lower 'slides'. I can think of no obvious reason, apart from the fixing of some sort of cover over the slidebars - either for safety in street tramway working, or as protection against abrasive material - eg. windblown sand/industrial sand. That said, I see no evidence of holes in these outer strips, for fixing bolts.....

Do we know where the loco worked, which might provide a clue?

Over to you, for confirmation/demolition!

If my supposition proves true, it should be reasonably easy to add the outer strips from fine NS strip?

Best wishes

Steve

[jon price]

Just realised I put Manning Wardle in error on the first image. Of course these are Hudson Clarkes

this is loco No9 of the Wrexham, Mold and Connah's Quay Railway, undated but probably c1902 when it was repainted in the black livery. It was built 1872 by Hudswell, Clarke and Rodgers and sold to Thomas Butlin &Co of Wellingborough who named it David. At some point it was sold back to Hudsons as WMCQR bought it from them in 1881. It was numbered 402B by the GCR in 1905 at which point it was reported to be in the shop at Rhosddu for a major overhall including "new slidebars, newcrossheads and new rod ends" but this isn't specificallty related to them as it was also having a new boiler, firebox, cab, and bunker (three years after a repaint!). It was scrapped in 1909

the railway also owned loco No7, bought new from Hudswell, Clarke and Rodgers in 1876, works no 178. (Watkinsons, Buckley Collieries, on the Buckley branch of the WMCQR bought works no 179 at the same time, naming it "Watkinson No2"). I have found no flat-on side photo of this loco, but this one appears to show a similar slidebar arrangement. Photo not dated. It was renumbered 401B by the GCR in 1905 and scrapped in 1909.

no7.jpg

[billbedford]

I'm trying (and failing) to understand how this crosshead on a Manning Wardle loco could be modelled. Any suggestions (preferably with simple diagrams)?

I would say it was either a three bar arrangement, with a single wide bar at the top, or four bar.

[John Palmer]

I did a trawl of Hudswell Clarke images on Google and came up with a further possible interpretation of the OP's photograph which, I think, answers the first of Steve's points.

Take a look at Hudswell Clarke No. 140 at http://www.embsayboltonabbeyrailway.org.uk/photos/no140.jpg. My interpretation of this photograph is that a chamfer has been planed from the edge of the slidebars, whilst the guide 'lips' on the crosshead have been correspondingly chamfered, such that no part of the crosshead protrudes beyond the profile of the slidebars, in cross section thusly:

crosshead.jpg

As can be seen such an arrangement preserves almost the full width of the crosshead's available bearing surface, and thereby simplifies the fitting of the white metal/bronze bearing inserts.

Making such slidebars in miniature seems straightforward enough, but forming a mating chamfer on the crosshead might not be so easy.

[jon price]

Maybe making the surface of the slidebar half round and the cross head a similar shape would be easier to manufacture