Union Tank Car 10-Q 2006 Q1 Quarterly report

Exhibit 32.2

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Union Tank Car Company (the “Company”) on Form 10-Q for the period ended March 31, 2006, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Mark J. Garrette, Principal Financial Officer of the Company, do hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

In witness whereof, I have executed this certification as of the 15^th day of May, 2006.

/s/ Mark J. Garrette

Mark J. Garrette

Principal Financial Officer