More Pre-Grouping Wagons in 4mm - the D299 appreciation thread.

[Asterix2012]

5 hours ago, magmouse said:

Regarding the tram car trolleys, it's curious that the shorter trucks were built immediately after the longer ones, when there seems little to gain in a shorter design, and a loss in flexibility of use. The shorter ones will have been marginally cheaper, and offered 3 1/4 inches more headroom, but I would have thought adding to the pool of 24" OH trucks would have been more useful? Possibly I am inappropriately applying a 21st century view of efficiency, flexibility and return-on-investment to a 19th century decision...

 

Nick.

A shorter truck might have been less liable to deform with the short and relatively heavy load of a team engine perhaps?

[Dave Hunt]

19 minutes ago, Compound2632 said:

 

To the Hon. Chairman of the Midland Railway Society,

 

Dear Sir,

 

The photo was taken at Devynock, Neath & Brecon Railway.

 

Your most obedient servant,

 

A. Pedant Esq. M.Inst.R.C. 

 

Interlaced crossing timbers are still classic Midland.

 

Dave

[Compound2632]

1 minute ago, kitpw said:

Talking of rabbit holes, your enthusiasm for the 40 ton trolley wagon (again in a post earlier today) which you contrasted with the more common angular shapes of that era took me down one the other day... into the world of fracture mechanics. It's particularly noticeable that the box beams on the sides of the 40 ton trolley are a pretty good demonstration of how to avoid stress concentrations or "stress raising" and to that extent, seemed to me to be ahead of its time. 

 

Getting my notes together in one document I realised No. 10018 had started out being rated to carry 50 tons. On the 1889 diagram sheet, it is simply "Long Armour Plate Truck"*; in the 31 December 1894 stock list, it's the only vehicle under the 50 tons heading; likewise in Plate 7 and Table 10 of S.W. Johnson's Presidential Address to the I.Mech.E., 1898:

 

 

In the  Sept 1898 diagram sheet at TNA it is "40 ton trolley" and subsequently, up to and including the diagram, D308. The Study Centre copy of the drawing, Drg. 611, is labelled "40 ton trolley" but that looks very much to have been stencilled on at the same time as the inscription "File No. 11/92" - a later addition. The original title seems to be "Armour Plate Truck" with no mention of capacity. There is also a somewhat ragged copy of Drg. 612 [MRSC 88-D1978] "Axlebox for 50 ton Armour Plate Truck.

 

The sinuous frame shape can indeed be contrasted with the angular fabricated frame of the pair of 30 ton trolleys of 1875 and their successors of 1897, which latter also feature in Plate 7 of Johnson's Address:

 

 

*In my notes I had mis-typed this as "Long Amour Plate Truck" which accounts for my abiding passion for this vehicle.

[kitpw]

27 minutes ago, Schooner said:

Oops

Yes, the Comet... Fatigue cracking seemed to remain less understood than it should have been given Inglis's insight.

 

The thing I remembered about stress concentration in the context of the 40 ton trolley* was the incident of a ship breaking up due to cracks radiating out from the right angled corners of the deck loading hatches: after that incident, steel plate decks were pierced with radius corners.  I couldn't find the reference and still can't but its date would be of interest.

 

*50 ton

 

Edited February 20, 2023 by kitpw
amendment to load capacity

[Compound2632]

You're taking me back to exhibits of at the old Birmingham Museum of Science and Industry: perspex shapes placed between angled polarisers which, when the button was pressed to apply force, displayed the stress patterns - especially around sharp corners.

[kitpw]

8 minutes ago, Compound2632 said:

You're taking me back to exhibits of at the old Birmingham Museum of Science and Industry: perspex shapes placed between angled polarisers which, when the button was pressed to apply force, displayed the stress patterns - especially around sharp corners.

I wish I'd seen that.

 

 

[Compound2632]

Those 30 ton trolleys:

 

 

 

 

[Embedded links to DY8849/50/51 on Science Museum website.]

 

Found while looking for something else, of course. Register says "Derby, Big Load at Handyside.

Edited February 20, 2023 by Compound2632

[MarcD]

Wrong skyline for Lancaster. it to flat and I cant find any church with a tower like that in lancaster on the flat area around the Midland Station. Thought it might be Morcambe but the Gas Works and the church dont line up.

 

Marc

Edited February 20, 2023 by MarcD

[Compound2632]

7 minutes ago, MarcD said:

Wrong skyline for Lancaster. it to flat and I cant find any church with a tower like that in lancaster on the flat area around the Midland Station.

 

Marc

 

Yes, I was thinking of Lancaster because of what looked like electrification gantries in the background, but then I realised the photos have the DY number embedded in the url, when one opens them in a new window, so I could check against the Derby Register. Location is Derby, as in now-amended text above. 

[corneliuslundie]

Any idea what they are? My first thought was bridge girders but not with that shape.

Jonathan

[magmouse]

 

Also oops.

[WFPettigrew]

40 minutes ago, Compound2632 said:

Derby, Big Load at Handyside.

That script writing on the final picture of the whatever-it-is  looks remarkably/suspiciously like "Handyside"???

[Compound2632]

1 minute ago, corneliuslundie said:

Any idea what they are? My first thought was bridge girders but not with that shape.

 

The Register just says "Big Load"! I suppose a railwayman doesn't care what it is, just how far it's out of gauge. Date is 27 June 1908. Does Handyside's order book survive?

[magmouse]

1 hour ago, Asterix2012 said:

A shorter truck might have been less liable to deform with the short and relatively heavy load of a team engine perhaps?

 

Yes, except they are both rated the same. At 15 tons, it is probably more a matter of the rating of the bearings than the wagon structure.

 

Nick.

[Compound2632]

5 minutes ago, magmouse said:

Yes, except they are both rated the same. At 15 tons, it is probably more a matter of the rating of the bearings than the wagon structure.

 

I'm thinking the size of that turntable giving access to Kitson's works, that Jamie mentioned, might be the reason.

 

 

[https://maps.nls.uk/view/125642461]

Edited February 20, 2023 by Compound2632

[magmouse]

57 minutes ago, Compound2632 said:

You're taking me back to exhibits of at the old Birmingham Museum of Science and Industry: perspex shapes placed between angled polarisers which, when the button was pressed to apply force, displayed the stress patterns - especially around sharp corners.

 

I'm old enough you have used that technique during my engineering degree. Remarkably, the method could not only show where the stresses concentrated, you could actually use it to do ball-park calculations, if you scaled the perspex model accurately.

 

Nick.

[magmouse]

1 minute ago, Compound2632 said:

 

I'm thinking the size of that turntable giving access to Kitson's works, that Jamie mentioned, might be the reason.

 

Ah, that would make sense.

 

Nick.

[magmouse]

12 minutes ago, corneliuslundie said:

Any idea what they are? My first thought was bridge girders but not with that shape.

Jonathan

 

One of these?

 

https://www.ribapix.com/lifting-bridge-garnet-street-shadwell-basin-wapping-wall-london_riba116611

 

Nick.

[Compound2632]

17 minutes ago, magmouse said:

One of these?

 

https://www.ribapix.com/lifting-bridge-garnet-street-shadwell-basin-wapping-wall-london_riba116611

 

Bingo! That particular bascule bridge was built in the 1930s but it's a dead ringer. 

 

Here's a short list of Scherzer rolling lift bascule bridges:

https://structurae.net/en/structures/bridges/scherzer-rolling-lift-bascule-bridges/list

The earliest there is from 1908 but in the Providence, Rhode Island.

 

There's one in Hull, Drypool Bridge, that has the same piece, but I can't find a date.

 

There's one (a pair) in Dublin, 1912.

Edited February 20, 2023 by Compound2632

[Compound2632]

25 minutes ago, Compound2632 said:

 

I'm thinking the size of that turntable giving access to Kitson's works, that Jamie mentioned, might be the reason.

 

21 minutes ago, magmouse said:

Ah, that would make sense.

 

Kitson's built a large number of Kirtley double-framed 0-6-0s, with 8' 0" + 8' 6" wheelbase, so it would have been madness if the turntable wasn't big enough for those. The wheelbase of the tram engine truck was 16' 0" and of the longer trolley, 20' 0". 

[Andy Hayter]

20 minutes ago, Compound2632 said:

 

Bingo! That particular bascule bridge was built in the 1930s but it's a dead ringer. 

 

Here's a short list of Scherzer rolling lift bascule bridges:

https://structurae.net/en/structures/bridges/scherzer-rolling-lift-bascule-bridges/list

The earliest there is from 1908 but in the Providence, Rhode Island.

 

There's one in Hull, Drypool Bridge, that has the same piece, but I can't find a date.

 

There's one (a pair) in Dublin, 1912.

A bit late for us

 

The bridge was opened in 1961 and replaced an old swing bridge, which was also called Drypool Bridge, or 'Salthouse Lane Bridge', which opened in 1889.

 

https://movable-hull.fandom.com/wiki/Drypool_Bridge

 

[WFPettigrew]

This thread goes round in circles.

 

A Scherzer Bascule bridge was erected over Buccleugh Dock in Barrow in 1907-8, this was a replacement structure taking the line to Ramsden Dock station, and one of two bridges in Barrow that I mentioned recently as also being possible weak points in the FR route for armour plate wagons!

 

The road bridge to Walney Island nearby was also built at the same time as a bascule lifting bridge. 

 

All the best

 

Neil

 

 

[Asterix2012]

2 hours ago, kitpw said:

Yes, the Comet... Fatigue cracking seemed to remain less understood than it should have been given Inglis's insight.

 

The thing I remembered about stress concentration in the context of the 40 ton trolley* was the incident of a ship breaking up due to cracks radiating out from the right angled corners of the deck loading hatches: after that incident, steel plate decks were pierced with radius corners.  I couldn't find the reference and still can't but its date would be of interest.

 

*50 ton

 

This occurred with the first welded ships, with riveted plates the stresses were not concentrated in the same area

[Compound2632]

18 minutes ago, WFPettigrew said:

This thread goes round in circles.

 

A Scherzer Bascule bridge was erected over Buccleugh Dock in Barrow in 1907-8, this was a replacement structure taking the line to Ramsden Dock station, and one of two bridges in Barrow that I mentioned recently as also being possible weak points in the FR route for armour plate wagons!

 

The road bridge to Walney Island nearby was also built at the same time as a bascule lifting bridge. 

 

I think we have it. I'd found the Walney bridge, but it wasn't a match. The Buccleuch bridge is:

 

 

[Embedded link to Wikimedia Commons.]

 

A photo here:

http://barrowisland.xara.hosting/docks4.htm

shows the quadrant better - it does seem to be the same as on the wagons. But according to that, they were in place in Barrow by 1907, whereas according to the date given in the Derby Registers, they didn't leave Derby until June 1908...

[MarcD]

Also could be an export order as the famous Pegasus Bridge over the Orne Canal, in Normandy, is the same design.

Marc