Ulrich,
I haven’t seen photos of the three initial BNSF AC4400CW. I assume they had the original design of GE steering trucks?
Only CSX and CP seem to like that design. It is possible they have sharper curves than UP!
Peter
Ulrich,
I haven’t seen photos of the three initial BNSF AC4400CW. I assume they had the original design of GE steering trucks?
Only CSX and CP seem to like that design. It is possible they have sharper curves than UP!
Peter
They had the same old HI -AD truck. The KCS has the steerable truck also.
Hi Peter,
the BNSF AC4400 had Hi-Ad trucks, no GE steering trucks.
Pic of a AC 4400 5600 (the first BNSF AC 4400 - Built in 1999): http://www.qstation.org/5600/5600_2.jpg
At this page you find a photo of new AC4400 5611 (Pic 6) and of BNSF GEVO 5724 (Pic 8) !!!
http://westbnsf.smrn.com/railroad%20photos/bnsf13.htm
All equipped with Hi-Ad trucks!
At the photo you see the extreme modifications at the cooling compartment of the ES44AC!
BTW: I got my Trains issue February 2004 yesterday - first was lost in post service here.
I not agree that the SD70ACe is that step into the future.
The bolsterless Hi-Ad construction isn´t old !!!
A RR must find out what´s the best and when UP and BNSF made the decision for Hi-Ad they know what they do!!!
NEVER FORGET:
GE offers two different trucks “BOLSTERLESS HI-AD” and BOLSTERLESS AND STEERABLE".
EMD offers only the HTCR II !!! [:D]
Ulrich,
Sorry, I must have been too tired when I wrote my post! I meant to ask about the UP locomotives with steering trucks. I did look at the links to the BNSF photos. The view of the GEVO engine unit is interesting.
And Hogger42, thanks for reminding me about the KCS AC4400CWs!
The principle of the bolsterless truck really began with the CN MLW C630M in the late 1960s, and was only adopted by GE after they took over MLW and became the owner of the designs and patents.
This design principle is actually older than the Alco Hi-Ad truck, which did use some rubber in the secondary springing, but was a conventional bolster design.
The MLW truck still had a centre pivot, but it wasn’t involved in supporting the carbody.
This pivot is no longer required in the GE Hi-Ad, but some drawings of the EMD HTCR II truck appear to show a central pivot of some kind. The rubber support springs of the EMD and GE designs are very similar. EMD do not produce a non-steering version of the truck, their only alternative being the bolster type HTC truck.
It does seem to be possible that the two GE designs are interchangeable, using the same rubber secondary springs in the same location. (I hadn’t thought of this until you indicated that UP had rebuilt their units). This would be consistent with other GE locomotive characteristics.
Peter
At EMD´s homepage is a page about HTCR II truck:
http://www.gmemd.com/en/locomotive/innovations/radial_bogie/index.htm
It´s without bolster, read the text ! at the pic it looks like “with bolster”.
An EMD customer has no opinion - Must buy HTCR II.
The steerable GE is an “EXTRA”, Hi-Ad is the standard. Customer must make a decision!
Who knows what had happen if EMD also offer a cheaper non radial bolsterless truck as option! UP´s SD70 M with another trucks? Possible!
The three UP AC4400 with the steerable´s are from one of the first orders but not the three “First of all” locomotives, first numbered 9997 to 9999. I had seen a photo of such an unit but don´t ask…Sorry! But I´m sure it was the normal steerable truck design
Possible it was in an UP directory .
Ulrich,
A truck can have a pivot without having a bolster. In a truck like the EMD standard HTC truck, a cast bolster, shaped like a letter “H” sits on top of the secondary springs (which are rubber pads on the HTC). The pivot is in the centre of the “stroke” across the “H” which sits on the truck with the “stroke” parallel to the rails.
On the MLW/Dofasco truck, there is no bolster and the weight of the unit is transferred directly from the frame to the truck through rubber pads (actually “sandwiches” of multiple layers of rubber and thin steel sheets to stop distortion). All movement of the truck is taken up by the rubber pads. However, the traction forces from the truck to the locomotive frame are absorbed through a pivot point on the frame that “floats” vertically and does not take any of the locomotive weight. It mates with a bearing on a truck cross member that is spring loaded in both horizontal directions to allow truck movement, but the forward/backward springs absorb all the haulage forces from the truck.
I think the pivot on the HTCR-II truck (if that’s what it is) acts in the same way, as well as locating the truck steering links on the body/frame.
In fact, all trucks must have some means of transferring the traction load to the frame. I don’t know how the GE Hi-Ad does this, but the MLW solution is very likely. Remember that the first CN GE units built at Montreal used the MLW truck, so GE have direct experience of it. The Australian CM30-8 units, illustrated in green and yellow on the GE website under “Dash-8”, also have MLW trucks.
Has anyone found photos of GE Hi-Ad trucks, not under locomotives, and viewed from above?
Peter
Ulrich,
I checked the GE truck photos in the “Field Guide”, and noticed that the Hi-Ad photo shows two shock absorbers horizontal but at an angle to the frame side between the second and third axles. This is exactly the same arrangement as the shock absorbers on the MLW trucks on Montreal M636 locomotives. So although it isn’t clear in the photo, I suggest that the pivot point on the GE Hi Ad is between the first and second axles, as it is on the MLW trucks. On the MLW trucks, the two shock absorbers “pointed” to the pivot
and I think the GE Hi-Ad is the same. This would mean that the pivot didn’t take any load, but just the traction forces.
Maybe the EMD HTCR-II is the same?
Peter
Peter
Peter,
that with the missing pivot was a mistake by me!
When I think bolsterless, I mean a truck that absorbe the traction forces to the frame with a rod construction. The new, here in Germany built electrics of New Jersey use this arrangement. Our 220 km/h locomotive series 101 is the “mother” of NJT engines and use this arrangement too.
There are two rods at the end of the frame connected to a place at the frame. The Austrian electro type 1044 show the four rods, each truck has two, between the trucks very clear.
But your right, there is no rod construction for the traction force in this engines, must be a pivot !!!
Ulrich,
I made an error myself! The pin is on the truck and the bearing and springs on the frame, at least on the MLW trucks. By coincidence, I printed the diagram of the NJT ALP-46 (from the Bombardier website) today! I’ll check to see if it shows the traction rods (at least that’s what we call them here!).
Peter
Peter,
I visit the Bombardier website a few minutes ago. In the ALP-46 drawing you see parts from the traction rods.
Under locomotive parts - trucks - you will find the also GE offered Blue Tiger. There you see the rods better at the drawing.
The Blue Tiger was built in Kassel by Adtranz. That plant was opend in the 1850´s as the Henschel Works. The most inovative locomotive work in Germany for the highspeed market from 1930 to 1990.
In the 1980´s Krupp in Essen become the owner, named it Krupp-Henschel.
Then comes Damiler Benz (Daimler Chrysler was later) and named the railway segment Adtranz. The name Henschel becomes history.
And today the plant is only a little part in the big Bombardier concern.
Today, there built a few hundred people locomotives together from parts that are built in Poland and other lowcost countrys. 30 years ago a few thousand people built complete engines. That´s progress!
The new Metra engines use rebuilt EMD 645 diesel. The new crankshaft were made in Poland!
Ulrich,
I have the Mehanoteknica model of the prototype Blue Tiger, perhaps I should check that. I have to repair the pilot at one end - it clips on (or should) but doesn’t lock in place any more. Otherwise, it is a really good model.
I visited Kassel in 1992. The part of town around the old railway station appeared to be having a hard time surviving then.
I will still have to look more closely at the EMD trucks to work out their arrangements!
Peter