Air and Dynamic Brakes
and Train Handling

I cannot tell you how many times I have been asked about this situation pertaining to the SD90/43MAC locomotives: "Whenever they are lead units, but configured in the Integrated Distributed Power (IDP) format, what circumstances are causing them to 'drop the anchor' (Place the train into emergency) without warning?"

Yes, this reporter has fallen prey to this unpleasant occurrence, too (Thankfully, my train was already stopped when it happened); yet in fairness, not all of the SD90/43MAC's are being struck by this condition. But it has also been happening with the IDP equipped locomotives of the BNSF Railroad, so we are not speaking about a limited case to one particular railroad.

This question has a yes and no answer. First, the no response: These emergencies do not tend to occur whenever the SD90/43MAC unit is setup in DP REMOTE ENABLED condition (On March 15th, train CCDSA-11 I worked out of McAlester, Oklahoma has as its remote unit SD90/43MAC No. 8117; its performance was as well as any of the DPU equipped GE locomotives that have been back there).

Now to the yes response: In the DP LEAD ENABLED status, the emergencies have been more prevalent. They have occurred, regardless of whether the remote unit linked to it was another SD90/43MAC, or one of the units which use the stand alone control box console format.

It has been confirmed that the situations leading to the emergencies are data timeouts and packet timeouts. The data timeouts possible cause is a rate feeding sequence problem between the IPM (Integrated Processor Module) and the CCC (Cab Consolidation Computer) in the ICE (Integrated Cab Electronics) system.

There is some belief that the amount of CCC capacity, after adding IDP to what it is already having to handle, is experiencing a reduction in its ability to perform what it needs to do adequately. The packet timeout is the result of a loss of communications for five seconds between the CCC and the IPM module.

In either case, when the timeout occurs, the ICE system will react by kicking in the safety system feature which gives you the emergency brake application results. You will also likely get one of the following in the row of warning indicators on the right ICE screen:

1. A series of blue squares which will say INVLD DATA (Invalid Data) or DATA TMOUT (Data Timeout), or

2. Two red squares: one saying AIR BRAKE FAIL, the other PCS OPEN. The left ICE screen will still display DISTRIBUTED POWER OPERATION; however, it will not show you anything about the status of the remote unit(s).

1. Take the MAC unit "off the line" via the isolation switch on the engine control panel.
2. In the circuit breaker cabinet in the cab, turn off these breakers in this order:

COMPUTER CONTROL
AIR BRAKE

3. Go into the Train Enclosure Unit (This is the large black box in the vestible area); in this cabinet, turn off the breaker switch on the Train Power Supply module.
4. Leave them off for two to four minutes.
5. Turn on the breakers in the reverse order you had turned them off.

This should now reconfigure the ICE screens into the conventional operations format. Then use the More Menu soft key on the right ICE screen to roadmap you to the Dist Pwr soft key selection.

After selecting Dist Pwr, there will appear message prompts and other helpful things which will guide you on how to perform the linking and setup procedures. Long Term: Static testing is now being conducted are part of determining the cures for these situations. Once everything meets the approval of all involved parties, retrofit modifications will be performed.

The eye catcher: Its power was a single unit, that being SD90/43MAC unit No. 8181.

Later on (during another tour of duty), I had the opportunity to visit with the engineer of that job. He had for me some questions about the locomotive since it was his first time to operate one.

I had some questions for him, too, such as: "How did the locomotive perform on Ray Hill?"

He said, "The train's speed got down to 5 MPH; which then was maintained all the way up the hill and over the crest at Juanita Drive.

"The tractive effort meter readout did go into the yellow zone (It was around 162,000 lbs). The locomotive really got down after it.

"There were some occassional squeals from the wheels; but the wheelslip control system response was super. I never gotten a wheel slip light. I stayed in Run 8 throttle the entire time. At no time did it do any lunging, jumping or "boogie shaking.

"I was really impressed by how it did".

Their runs have included trips out of Pueblo, Colorado to Denver, through North Platte to Proviso, Illinois, then from there to Los Angeles and back to North Platte (The jobs have mainly been intermodal trains).

Reports are the locomotives have been performing very well. Up to presstime, the trio had gone back to Pueblo for a routine checkup before coming back on the property for more road testing.

Also involved with performance testing on intermodal trains are prototype C60AC locomotives UP 7002 and UP 7008. Some of their runs include trips over the former WP lines into northern California. The rest of the group (The other eight units) remain in soda ash unit train service between Green River, Wyoming and North Platte.

Until recently, the only times when the famous SD70MAC units of the BNSF Railroad would make their appearances into Fort Worth was by way of their company's unit coal train operations to Texas utilities.

Then along came UP unit coal train job 2CBTHS-05 (Black Thunder mine to Halstead), which made its way into Fort Worth on April 9th. The job was of conventional format, with 112 loads, 14953 gross tons, with this power lashup out of North Platte:

UP 8156 (SD90/43MAC)
BN 9639 (SD70MAC)
CNW 8814 (C44AC)

Now to the main event: Due to a problem which surfaced on the UP 8156, the BN 9639 became the new lead unit for the consist at Parsons, Kansas. I hope to get to speak with the engineer to gather his thoughts about the locomotive itself and how it did on Ray Hill for a future issue (I did get to chat with the conductor).

The lashup returned to Fort Worth on April 11th on train 2CHSBT-09, with 134 empties in the conventional format. The BN 9639 ended its run on this job as the lead unit upon arrival at North Platte.

1. A new system general order is now in effect which revises TTSI Item 10 to ABTH Rule 31.9.1. The comments section outlines why the alterations were necessary. Do keep in mind that these procedures also govern trains operating with equivalent devices.

2. Another system general order issuance addresses changes to GCOR Rules 5.9.5 along with ABTH Rules 30.8.2, 30.8.3 A5, and 30.9.1. Its focus is on displays of auxilliary lights for locomotives (More coverage on this subject is touched upon by Fort Worth Division General Notice No. 57).

There is also outlined a new requirement to the instructions for performance of daily locomotive inspections; this involves verifying that the locomotive(s) have not reached the expiration date shown on the Blue card.

3. A system general notice is now in place notifying locomotive engineers about precautions necessary with the forced leading feature on locomotives equipped with the WABCO E3102 brake system.

Be aware that this instruction will also apply to any locomotives that are equipped with the KNORR CCB system. Presently, all BNSF SD70MAC and SD75MDC, along with CSXT SD70MAC, C44AC and C60AC, and UP C44/60AC units No. 7050, No. 7051, and the upcoming 7300 series orders use the CCB system.

Have you ever wondered what is the most powerful thing in this world today?
The answer: It's called prayer.
If you would like to know more about this, see Psalms 31 in the Old Testament.

Marcel is a Fort Worth Based Locomotive Engineer.