11-K for SIP

EXHIBIT 99.4
SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549
FORM 11-K
(Mark One)
[X]		ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2004
OR
[ ]		TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________ to __________.
Commission File No. 1-768
SOLAR TURBINES INCORPORATED SAVINGS AND INVESTMENT PLAN (Full title of the Plan)
CATERPILLAR INC. (Name of issuer of the securities held pursuant to the Plan)
100 NE Adams Street, Peoria, Illinois 61629 (Address of principal executive offices)

SIGNATURES
Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Company has duly caused this annual report to be signed on its behalf by the undersigned, hereunto duly authorized.
	SOLAR TURBINES INCORPORATED SAVINGS AND INVESTMENT PLAN
	CATERPILLAR INC. (Issuer)

May 26, 2005	By:	/s/ David B. Burritt

		Name:	David B. Burritt
		Title:	Vice President and Chief Financial Officer

In our opinion, the accompanying statement of net assets available for benefits and the related statement of changes in net assets available for benefits present fairly, in all material respects, the net assets available for benefits of the Solar Turbines Incorporated Savings and Investment Plan (the "Plan") at December 31, 2004 and December 31, 2003, and the changes in net assets available for benefits for the years then ended, in conformity with accounting principles generally accepted in the United States of America. These financial statements are the responsibility of the Plan's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

Our audits were conducted for the purpose of forming an opinion on the basic financial statements taken as a whole. The supplemental Schedule of Assets Held at End of Year is presented for the purpose of additional analysis and is not a required part of the basic financial statements but is supplementary information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. This supplemental schedule is the responsibility of the Plan's management. The supplemental schedule has been subjected to the auditing procedures applied in the audits of the basic financial statements and, in our opinion, is fairly stated in all material respects in relation to the basic financial statements taken as a whole.

EXHIBIT A
Solar Turbines Incorporated Savings and Investment Plan Statement of Net Assets Available for Benefits December 31, 2004 and 2003

(in thousands of dollars)			2004		2003

Investments
	Interest in the Caterpillar Investment Trust		$	72,854	$	36,052
	Participant loans			2,627		2,303
	Other investments - registered investment companies in participant directed brokerage accounts			1,024		934

	Total Investments			76,505		39,289

Participant contributions receivable				68		-
Employer contributions receivable				17		-

		Net assets available for benefits	$	76,590	$	39,289

The accompanying notes are an integral part of these financial statements.

EXHIBIT B
Solar Turbines Incorporated Savings and Investment Plan Statement of Changes in Net Assets Available for Benefits Years Ended December 31, 2004 and 2003

(in thousands of dollars)				2004			2003

Contributions
Participant				$	5,323		$	2,878
Employer					1,111			-

		Total contributions			6,434			2,878

Investment income
Plan interest in net investment income of Master Trust					9,198			9,442
Interest on participant loans					144			155
Net appreciation in fair value of registered investment companies in participant directed brokerage accounts					89			164

			Net investment income		9,431			9,761

Deductions
	Withdrawals				(6,729	)		(1,931	)
Transfers
	Transfers from (to) other plans, net				28,165			(1,812	)

Increase in net assets available for benefits					37,301			8,896

Net assets available for benefits
Beginning of year					39,289			30,393

End of year				$	76,590		$	39,289

The accompanying notes are an integral part of these financial statements.

The Plan is a contributory defined contribution plan established by Solar Turbines Incorporated (the "Company"), a 100 percent-owned subsidiary of Caterpillar Inc., to enable eligible employees of the Company and its subsidiaries (the "participating employers") to accumulate funds. The Plan is subject to the provisions of the Employee Retirement Income Security Act, as amended ("ERISA").

Hourly employees of the participating employers who meet certain age, service and citizenship or residency requirements are eligible to participate in the Plan. Participation commences upon an eligible employee filing an application with the Plan’s recordkeeper. Participating eligible employees (the "participants") may elect to make after-tax contributions to the Plan and also defer a portion of their compensation until retirement through pre-tax contributions.

Effective January 14, 2004, Solar Turbines Incorporated Union employees ceased to contribute to Part 1 of the Caterpillar Inc. Employees’ Investment Plan (“EIP Part 1”). These employees immediately became eligible to make after-tax contributions and receive matching employer contributions on these contributions in the existing Solar Turbines Incorporated Savings and Investment Plan (consistent with previous participation in EIP Part 1). The Plan balance transferred out of EIP Part 1 into the Plan as of January 14, 2004, was $29,647,431.

Accounts are separately maintained for after-tax and pre-tax contributions by the Plan’s recordkeeper for each participant. The participant's after-tax contribution account is credited with the participant contributions, employer contributions and an allocation of Plan earnings. The participant’s pre-tax contribution account is credited with participant contributions as defined below and an allocation of Plan earnings. Allocations of earnings are based on participant account balances, as defined. The benefit to which a participant is entitled is the benefit that can be provided from the participant's vested account.

The Plan provides for participant loans against eligible participants' account balances. Eligible participants obtain participant loans by filing a loan application with the Plan’s recordkeeper and receiving approval thereof. Loan amounts are generally limited to the lesser of $50,000 or 50 percent of the individual participant's vested account balance, with certain regulatory restrictions. Each loan shall specify a repayment period that shall not extend beyond five years. However, the five-year limit shall not apply to any loan used to acquire any dwelling unit which within a reasonable time is to be used (determined at the time the loan is made) as the principal residence of the participant. Loans bear interest at the prime interest rate plus 1 percent rounded to the nearest whole percent, as determined at the time of loan origination. Repayments, including interest, are made through after-tax payroll deductions and are credited to the individual participant's account balance. Participant loans have various maturity dates through May 30, 2014, with varying interest rates ranging from 5 to 11 percent.

Participant contributions can also be made through pre-tax compensation deferral as elected by the participants and are contributed to the Plan by the participating employers. Participants who are at least 50 years old by the end of the calendar year are allowed by the Plan to make a catch-up contribution for that year. The maximum amount of catch-up contributions a participant could make in 2004 and 2003 was limited to $3,000 and $2,000, respectively. The compensation deferral (including catch-up contributions) was limited by the Internal Revenue Code to $13,000 ($16,000 for age 50 or older) in 2004 and $12,000 ($14,000 for age 50 or older) in 2003.

*	Caterpillar Stock Fund	*	Preferred Asset Allocation Fund
*	Preferred Stable Principal Fund	*	Preferred Fixed Income Fund
*	Preferred Short-Term Government Securities Fund	*	Preferred Small Cap Growth Fund
*	Preferred Money Market Fund	*	US Equity Broad Index Fund
*	Preferred Value Fund	*	Preferred Mid Cap Growth Fund
*	Preferred International Value Fund	*	Preferred International Growth Fund
*	Preferred Large Cap Growth Fund

*	Caterpillar Stock Fund	*	Preferred Small Cap Growth Fund
*	Preferred Stable Principal Fund	*	US Equity Broad Index Fund
*	Preferred Short-Term Government Securities Fund	*	Preferred Mid Cap Growth Fund
*	Preferred Money Market Fund	*	Preferred International Growth Fund
*	Preferred Value Fund	*	Model Portfolio - Income
*	Preferred International Value Fund	*	Model Portfolio - Conservative Growth
*	Preferred Large Cap Growth Fund	*	Model Portfolio - Moderate Growth
*	Preferred Asset Allocation Fund	*	Model Portfolio - Growth
*	Preferred Fixed Income Fund

The Model Portfolios were added as investment options in October 2003. Each portfolio contains a specific mix of the Plan’s core 401(k) investments. Each portfolio’s mix of stocks and bonds is automatically rebalanced on the last business day of each calendar quarter. The targeted percentage of stocks and bonds in each of the Model Portfolios is as follows:

Participants are immediately fully vested in all participant contributions (pre-tax and after-tax) and earnings thereon. Participants also vest immediately in the Company's matching contributions and the earnings thereon. Upon termination of employment for any reason, including death, retirement or total and permanent disability, or upon Plan termination, the vested balance in participants' accounts is distributable in cash unless the participant (or beneficiary) elects to receive Company shares in kind. The value of any full or fractional shares paid in cash will be based upon the average price per share the Trustee receives from sales of Company shares for the purpose of making the distribution.

The Plan is administered by the Vice President - Human Services Division of Caterpillar Inc. who is responsible for non-financial matters, and the Benefit Funds Committee of Caterpillar Inc. which is responsible for financial aspects of the Plan. Caterpillar Inc. and the Benefit Funds Committee have entered into a trust agreement with The Northern Trust Company (the Trustee) to receive contributions, administer the assets of the Plan and distribute withdrawals pursuant to the Plan.

Although it has not expressed any intent to do so, the Company has the right under the Plan at any time to terminate the Plan subject to provisions of ERISA. In the event of Plan termination, Plan assets will be distributed in accordance with the provisions of the Plan.

The Plan obtained its latest determination letter on July 7, 2000, in which the Internal Revenue Service stated that the Plan, as then designed, was in compliance with the applicable requirements of the Internal Revenue Code. The Plan has been amended since receiving the determination letter; however, the Plan administrator believes that the Plan is currently designed and being operated in compliance with the applicable requirements of the Internal Revenue Code. Therefore, no provision for income taxes has been included in the Plan's financial statements.

The Plan’s interest in the Caterpillar Investment Trust is valued as described in Note 3. Shares of registered investment companies included in the self-directed fund option are valued at quoted market prices which represent the net asset value of shares held by the Plan at year-end. Loans are valued at estimated fair value consisting of principal and any accrued interest. Interest on investments is recorded as earned. Dividends are recorded on the ex-dividend date. Purchases and sales of securities are recorded on a trade-date basis.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, income and benefit payments. Actual results could differ from those estimates. The Company believes the techniques and assumptions used in establishing these amounts are appropriate.

The Plan provides for various investment options in any combination of stocks, bonds, fixed income securities, mutual funds and other investment securities. Investment securities are exposed to various risks, such as interest rate, market and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities could occur in the near term and that such changes could materially affect participants' account balances and the amounts reported in the statement of net assets available for benefits. Approximately 61 percent of the Plan’s investments are invested in the Caterpillar Stock Fund of the Caterpillar Investment Trust.

3. Master Trust

Under a Master Trust agreement with The Northern Trust Company (the "Trustee"), Part 2 of the Caterpillar Inc. Employees' Investment Plan (EIP), the Caterpillar 401(k) Plan, the Solar Turbines Incorporated Savings and Investment Plan and the Caterpillar Inc. Tax Deferred Savings Plan pool their investments in the Caterpillar Investment Trust (the "Master Trust") in exchange for a percentage of participation in the Trust.

The percentage of the Plan's participation in the Master Trust was determined based on the December 31, 2004 and 2003 fair values of net assets, as accumulated by the Trustee for the investment fund options chosen by the participants of each plan. At December 31, 2004 and 2003, the Plan's pro rata interest in the quoted fair values of net assets of the Master Trust was 1.90 percent and 1.10 percent, respectively.

The Master Trust's investments are stated at fair value. Common stock and cash and cash equivalents are valued at quoted market prices. Shares of registered investment companies are valued at quoted market prices that represent the net asset value of shares held by the Master Trust at year-end. Common and collective trust investments are valued at the fair value of the underlying investments.

(in thousands of dollars)	2004		2003

Caterpillar Inc. common stock	$	1,948,465	$	1,706,596
Preferred Large Cap Growth Fund		322,973		293,950
Preferred Stable Principal Fund		291,792		262,634
Preferred Value Fund		268,221		232,908
Preferred Money Market Fund		-		187,112

(in thousands of dollars)		2004			2003

Investments, at fair value
Cash and cash equivalents		$	23,882		$	18,475
Caterpillar Inc. common stock, 19,982,212 and 20,556,439 shares, respectively			1,948,465			1,706,596
Registered investment companies			1,495,349			1,239,652
Common and collective trusts			370,554			308,580

	Total investments		3,838,250			3,273,303
Dividend and interest receivable			36			13
Other, net			(16	)		11,581

	Net assets of the Master Trust	$	3,838,270		$	3,284,897

	Plan’s interest in the Master Trust	$	72,854			36,052

(in thousands of dollars)			2004		2003

Investment income
Interest			$	-	$	255
Dividends				32,832		21,746
Net appreciation in fair value of:
	Common stock			298,996		693,700
	Registered investment companies			111,831		198,943
	Common and collective trusts			15,407		17,443

		Net Master Trust investment income	$	459,066	$	932,087

		Plan’s interest in net Master Trust investment income	$	9,198	$	9,442

The Master Trust invests mainly in the Preferred Group of Mutual Funds, registered investment companies that are sponsored by Caterpillar Investment Management Ltd. (CIML), a wholly-owned subsidiary of Caterpillar Inc. The investment options available to the participants are summarized in Note 1 and include the Caterpillar Stock Fund. The Master Trust also invests in the US Equity Broad Index Fund, which is sponsored and managed by The Northern Trust Company, the Trustee for the Master Trust.

SCHEDULE I
Solar Turbines Incorporated Savings and Investment Plan EIN 36-3214040 Schedule H, Line 4i - Schedule of Assets Held at End of Year December 31, 2004

(a)	(b)	(c)		(d)		(e)
	Identity of issue, borrower, lessor or similar party	Description of investment, including maturity date, rate of interest, collateral, par or maturity value		Cost		Current value

*	Caterpillar Inc.	Caterpillar Investment Trust			**	$	72,853,869

	Harris Direct	Participant-directed brokerage accounts invested in registered investment companies			**		1,023,515

*	Participant loans receivable	Participant loans, various maturity dates through May 30, 2014, various interest rates ranging from 5% to 11%			-		2,627,172

			Total Investments			$	76,504,556

* Denotes party in interest.
** Cost information is not applicable for participant directed investments.

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (No. 2-97450, as amended and No. 33-37353) of Caterpillar Inc. of our report dated May 24, 2005 relating to the financial statements of the Solar Turbines Incorporated Savings and Investment Plan, which appears in this Form 11-K.

*	Income	20% stocks and 80% bonds
*	Conservative Growth	40% stocks and 60% bonds
*	Moderate Growth	60% stocks and 40% bonds
*	Growth	80% stocks and 20% bonds