7mm Richards P48 US Thread
- Thread starter richard carr
- Start date
Scale7JB
Western Thunderer
I could happily have spent an awful lot more!!Greetings, chaps!! Hope you all spent far too much!!
JB.
Big Train James
Western Thunderer
Hmmmm, I think my total for model railroad product was $30. Four sets of Microscale decals, and two spare Red Caboose gp9 fuel tanks. There's just not much available that I want or need, for whatever reason.
By the way, I think there was discussion on WT previously about the lack of availability of Red Caboose fuel tanks? The guy from Des Plaines was selling parts at the show and seemed to have ample supply in stock. I could be misremembering.
Jim
By the way, I think there was discussion on WT previously about the lack of availability of Red Caboose fuel tanks? The guy from Des Plaines was selling parts at the show and seemed to have ample supply in stock. I could be misremembering.
Jim
Stephen
Western Thunderer
Guilty as charged…….Greetings, chaps!! Hope you all spent far too much!!
Cheers,
Stephen
garethashenden
Western Thunderer
The kit I bought came without one. That may be what you're thinking of. They were happy to supply it when I asked.
Big Train James
Western Thunderer
That's probably it. It was definitely a vague memory. 
richard carr
Western Thunderer
As you all know several of us went to the Chicago O Scalers March meet last weekend. I have to admit that I did buy a few bits and pieces while I was there.
The first thing was this GP7, a sunset models one from last year
The first thing was this GP7, a sunset models one from last year
richard carr
Western Thunderer
I also got a few box cars
These 3 were all built from Kits and were ready to run P48. The couplings are using those extended Kadee boxes.
This one is an Atlas trainman boxcar that has been weathered, and an internal load fitted.
And finally a berwick overheight boxcar from Atlas.
These 3 were all built from Kits and were ready to run P48. The couplings are using those extended Kadee boxes.
This one is an Atlas trainman boxcar that has been weathered, and an internal load fitted.
And finally a berwick overheight boxcar from Atlas.
JasonD
Western Thunderer
Aaaaah Jordan ... Nth American O-scale 2-rail ... still the best-kept secret. Get saving for March 2025 in Chicago:
And don't forget the Winchester Meet nearer home provisionally on Saturday 26 October 2024. With any luck we'll have the details confirmed and I'll have done a list of what I'm putting on my tables.
And don't forget the Winchester Meet nearer home provisionally on Saturday 26 October 2024. With any luck we'll have the details confirmed and I'll have done a list of what I'm putting on my tables.
Stephen
Western Thunderer
Jordan - there was one stall at Chicago (probably the one that Richard purchased the box cars from) which was literally only selling SOO Line vehicles, abet in P48 scale.....Not at all jealous of those boxcars... no no nooo.... not at all, in any way whatsoever....
After all, they don't fit my track....
Looks like the kits are the same SOO 7-post one that we have one each already?
You'd have had a field day......if you got there before Richard did!
Cheers,
Stephen
Jordan
Mid-Western Thunderer
richard carr
Western Thunderer
Hi Jordan
When I saw them I did think of you.
I'm thinking that I should have bought the SW8/9 switcher in Soo red white livery, but I didn't, it was P48 too.
There was also a really nice Wisconsin Central boxcar.
I did though find this.
An SD40 -T2 tunnel motor with snoot nose.
I was told that it was an Oriental Ltd brass loco, it has been painted and a few extra bits added, it has DCC sound but it is OW5 at the moment.
The seller said it had been P48 but he had converted back to OW5 as he thought it would be easier to sell. He'd used the P48 wheel sets on something else. What a shame for me.
It's a nice model, it just needs a stay alive to aid the pickups.
Richard
When I saw them I did think of you.
I'm thinking that I should have bought the SW8/9 switcher in Soo red white livery, but I didn't, it was P48 too.
There was also a really nice Wisconsin Central boxcar.
I did though find this.
An SD40 -T2 tunnel motor with snoot nose.
I was told that it was an Oriental Ltd brass loco, it has been painted and a few extra bits added, it has DCC sound but it is OW5 at the moment.
The seller said it had been P48 but he had converted back to OW5 as he thought it would be easier to sell. He'd used the P48 wheel sets on something else. What a shame for me.
It's a nice model, it just needs a stay alive to aid the pickups.
Richard
richard carr
Western Thunderer
Hi Graham
Most of the railroads that ran through long tunnels in the mountains had issues with exhaust fumes. With steam it was a big problem and Southern Pacific solved the problem with the cab forwards. It was still an issue with diesels, where they tended to have the air intakes mounted high on the body so that the trailing locos were ingesting too much exhaust from the locos in front. To solve this the "Tunnel Motors" had their air intakes fitted just above the walk ways, the 3rd photo shows these clearly.
The snoot nose refers to the elongated nose on this loco which was to be used to house control equipment to allow them to be mid train power.
As far as I have read this wasn't actually used very often in practice.
Richard
Most of the railroads that ran through long tunnels in the mountains had issues with exhaust fumes. With steam it was a big problem and Southern Pacific solved the problem with the cab forwards. It was still an issue with diesels, where they tended to have the air intakes mounted high on the body so that the trailing locos were ingesting too much exhaust from the locos in front. To solve this the "Tunnel Motors" had their air intakes fitted just above the walk ways, the 3rd photo shows these clearly.
The snoot nose refers to the elongated nose on this loco which was to be used to house control equipment to allow them to be mid train power.
As far as I have read this wasn't actually used very often in practice.
Richard
John57sharp
Western Thunderer
Tis a thing of great beauty.
John
John
Yorkshire Dave
Western Thunderer
This also explains why you require low level air intakes in tunnels - especially long tunnels where there is a greater chance of fuel being unburnt.
A look at the Cotton Belt Tunnel Motor at the end of the first consist would explain why. Although tunnel #5 is 358m long exhaust fumes can have an effect at depleting the oxygen. You have to view it on YouTube.
In steam days and before the Cab Forwards the Southern Pacific developed breathing apparatus for operating trains in long tunnels.
https://www.pinterest.co.uk/pin/the...-that-had-to-navigate-th--458804280783855077/
mickoo
Western Thunderer
To be pedantic, the air intakes were not moved, they're still in the same place up high behind the cab, that's the engine intake.
Exhaust wasn't the problem, it was the heat which as we all know from physics heads to the top of an enclosure. The problem was simply that the engines could not get enough cooled air over the radiators.
The radiator intakes are normally also at high level and vent out through the fans on the top, but they didn't work well in SP's long and numerous tunnels over Donner, often overheating and shutting down; that put extra stress on the remaining engines and in a domino effect several would fail and the train stall, not good if the manned helpers were stuck in a tunnel.
To overcome this SP trialed 'elephant ears' on standard engines, these worked by shielding the intake from the hot air near the top and dragged cooler air from lower down near the walkway. Two classes received elephant ears, SD45 and GP40X
The SD45 comes in two versions, round top and angular.
Australian Pacific National XR class still have them fitted....or did until recently.
The trials with the elephant ears were successful, so when SP and DRG ordered new SD40 & SD 45 EMD revised the design to move the radiator intake to low level near the walkway, they also revised the radiator placement and moved it above the fans; thus, tunnel motors were born.
The GP15 also has a low level radiator intake but that's not for tunnels, the rad core follows the same design at the tunnel motors where the fans are below the radiators, therefore the traditional waffle intake won't work.
One other type of radiator cover was fitted to some GE U boats, both SP and ATSF had them, these are not engine intake shrouds but sound baffles as the fans were too noisy.
Exhaust wasn't the problem, it was the heat which as we all know from physics heads to the top of an enclosure. The problem was simply that the engines could not get enough cooled air over the radiators.
The radiator intakes are normally also at high level and vent out through the fans on the top, but they didn't work well in SP's long and numerous tunnels over Donner, often overheating and shutting down; that put extra stress on the remaining engines and in a domino effect several would fail and the train stall, not good if the manned helpers were stuck in a tunnel.
To overcome this SP trialed 'elephant ears' on standard engines, these worked by shielding the intake from the hot air near the top and dragged cooler air from lower down near the walkway. Two classes received elephant ears, SD45 and GP40X
The SD45 comes in two versions, round top and angular.
Australian Pacific National XR class still have them fitted....or did until recently.
The trials with the elephant ears were successful, so when SP and DRG ordered new SD40 & SD 45 EMD revised the design to move the radiator intake to low level near the walkway, they also revised the radiator placement and moved it above the fans; thus, tunnel motors were born.
The GP15 also has a low level radiator intake but that's not for tunnels, the rad core follows the same design at the tunnel motors where the fans are below the radiators, therefore the traditional waffle intake won't work.
One other type of radiator cover was fitted to some GE U boats, both SP and ATSF had them, these are not engine intake shrouds but sound baffles as the fans were too noisy.
Last edited:
mickoo
Western Thunderer
Not quite Dave, yes hot air gives unburnt fuel and that's exactly what's happening in that video, it is caused by the engine intake being at high level, but as noted above the engine intake was never moved, even tunnel motors suffer from unburnt fuel, it ran rich but it still ran and that was the critical factor, aka, not stalling.
The downside to running rich is a loss of power so SP would often over power trains knowing that in hot long tunnels they would depreciate HP/tonnage.
The EMD car body has remained pretty much unchanged from the SD9, there are four main compartments, the first being the electrical, the second the clean air cabinet, the engine room and the radiator section and each is separate from the other.
The SD50 below is a good idea of how they look inside, though on the SD50 they moved the dynamic brakes from over the engine to ahead of the clean air room as it was cooler and they worked better.
Item #51 is the clean air intake and feeds into the clean air room (red box), from this enclosure air for traction motors is take and air for engine intake is also take through filters #10. Air then feeds into the turbo which on EMD engines is at the front, in and around item #7.
Conversely the radiator section is at the rear (green box) and intakes through items #51, the air then passes through the radiators (#25) and expels through the roof fans (#26).
GE on the other hand have the turbo at the rear and the engine intake filters are a part of the radiator cabinet at the rear, as are the traction motor blowers, GE already designed their engines with lower level intakes and did not suffer from fuel enrichment, though you'd have to question that given some of the volcanic displays GE's can exhibit.
GE engine intake circled, this is a generic location but it's usually in and around this area.
mickoo
Western Thunderer
Knew I had these somewhere, took a bit of finding, view from inside a tunnel motor rad section looking out
View from inside rad section looking at front wall bulkhead, note it's solid, no engine intake.
On tunnel motors the radiators are mounted above the fans, conventional EMD rad groups have fans on top.
View from inside rad section looking at front wall bulkhead, note it's solid, no engine intake.
On tunnel motors the radiators are mounted above the fans, conventional EMD rad groups have fans on top.