Green’s Dictionary of Slang

rat n.2

[abbr. rattler n.]

(US Und.) a train; thus rat stand, a railway station.

[US]Jackson & Hellyer Vocab. Criminal Sl. 68: rat [...] Passenger train; street car. A contraction of ‘rattler.’.
[US]Charleston (WV) Daily Mail 12 Mar. 3/4: Rat stand – Railroad station.
[US]J.L. Kuethe ‘Prison Parlance’ in AS IX:1 27: rat [...] A train [...] rat stand. A railroad station.
[US]Monteleone Criminal Sl. (rev. edn).
[US]Goldin et al. DAUL 174/2: Rats. 1. Freight cars. 2. Any railroad train; street cars. [Ibid.] 175/1: Rat stand. A rural railroad station.

In compounds

In phrases

on the rats

(US Und.) breaking into and stealing from freight-cars.

[US]Monteleone Criminal Sl. (rev. edn).
[US]Goldin et al. DAUL 174/2: Rats, on the. Engaged in, or by means of, freight-car robberies.