RCU's, "Pushers", Whatever Over Aurora Sub

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RCU's, "Pushers", Whatever Over Aurora Sub

Postby Gilbert B Norman » Fri Jan 08, 2016 11:52 am

While evidently use of RCU's (Pushers; what's the real name on BNSF; anyone?) Is quite common on BNSF, they had been rare over Aurora Sub.

However, since New Year's, they have become the rule on any class of train - oil, grain, coal, containers, merchandise.

Did something occur to prompt this operational change; could it just be my imagination?

Enquiring mind wants to know.
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Re: RCU's, "Pushers", Whatever Over Aurora Sub

Postby doepack » Thu Jan 14, 2016 2:25 am

Gilbert B Norman wrote:While evidently use of RCU's (Pushers; what's the real name on BNSF; anyone?) Is quite common on BNSF, they had been rare over Aurora Sub.

However, since New Year's, they have become the rule on any class of train - oil, grain, coal, containers, merchandise.

Did something occur to prompt this operational change; could it just be my imagination?

Enquiring mind wants to know.


If you're referring to an additional locomotive(s) "pushing" from the hind end, the proper industry-wide term is distributed power unit, or DPU. Can also be seen mid-train as well.

And it's not just your imagination or only BNSF, they've been showing up in increasing numbers along UP's Geneva sub as well...
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Re: RCU's, "Pushers", Whatever Over Aurora Sub

Postby GWoodle » Sat Feb 20, 2016 8:44 pm

[quote="Gilbert B Norman"]While evidently use of RCU's (Pushers; what's the real name on BNSF; anyone?) Is quite common on BNSF, they had been rare over Aurora Sub.

However, since New Year's, they have become the rule on any class of train - oil, grain, coal, containers, merchandise.

Did something occur to prompt this operational change; could it just be my imagination?



Seems to be 2 changes. Having lights on the rear end instead of an EOT device. Not sure about better brake controls? For operations, better fuel economy pushing/pulling trains. Likely to see them anywhere.
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Re: RCU's, "Pushers", Whatever Over Aurora Sub

Postby rch » Thu Apr 28, 2016 4:04 pm

In cold weather it is difficult to get the airflow down low enough to pass an airflow/leakage test. Having a locomotive on the other end of the brake pipe helps get the airflow down, besides the benefit of having power at each end of the train.
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Re: RCU's, "Pushers", Whatever Over Aurora Sub

Postby Engineer Spike » Wed Jun 15, 2016 9:12 pm

Part of the problem on long unit trains is knuckle strength, and forces on the rails. By having more than one set of power, which is distributed throughout the train, these problems are solved. The C&I, with its many hills might require trains to have more power than is practical in one location.

DP does help charge the train faster. The brake is cut in on each remote consist. The brakes also set faster, since the air is exhausted from each consist too. Flow is not an area where the type of power matters. I don't know what BN's rules are, but my airbrake boos says that the flow must be below 60 CFM, if one adds the flow from each consist. It seems certain that this is a federal rule, but I'd have to look it up. What is helped is the brake pipe gradient. If all power was on the head end, especially on long trains, in cold weather, the last car may not have enough pressure, on the tail end. That pressure must be within 15 psi of the feed valve setting. The DP unit will keep the pressure more uniform.
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