John Olin
Executive Vice President and Chief Financial Officer at Westinghouse Air Brake Technologies
Thanks, Rafael, and hello, everyone. Turning to Slide 8, I will review our first quarter results in more detail. In the first quarter, we continued to see the underlying momentum that we experienced as we exited last year. As expected, both revenue growth and operating margin growth were overshared in Q1 versus our expectations for full year growth.
As we discussed in the last quarter call, we expected both revenue and margin growth to be higher in the first half versus the second half. While we continue to expect growth in the second half, we expect it to be at a much more tempered pace than the first half. Sales for the first quarter were $2.5 billion, which reflects a 13.8% increase versus the prior year. Sales growth in the quarter was driven by the Freight segment, especially in our equipment and services groups.
For the quarter, GAAP operating income was $412 million, driven by higher sales, improved gross margin and focused cost management. Adjusted operating margin in Q1 was 19.8%, up 3.4 percentage points versus the prior year. This increase was driven by improved gross margin of 2.4 percentage points and driven by operating expenses, which grew at a slower rate than revenue, increasing our Q1 margin by an additional 1.0 percentage points.
GAAP earnings per diluted share were $1.53, which was up 64.5% versus the first quarter a year ago. During the quarter, we had pre-tax charges of $10 million for restructuring, which were primarily related to our Integration 2.0 and our portfolio optimization initiative to further integrate and streamline Wabtec's operations.
As you may recall, Integration 2.0 is expected to drive $75 million to $90 million of run rate savings by 2025, and our portfolio optimization initiative will eliminate roughly $110 million of low-margin, non-strategic revenue while reducing manufacturing complexity. In the quarter, adjusted earnings per diluted share was $1.89, and up 47.7% versus prior year. Overall, Wabtec delivered another solid quarter, demonstrating the underlying strength of the business.
Turning to Slide 9. Let's review our product lines in more detail. First quarter consolidated sales were up 13.8%. Equipment sales were up 30.2% from last year's first quarter driven by robust sales of mining equipment and higher deliveries of new locomotives. Component sales were up 13.6% versus last year, driven by increased sales of industrial products higher international sales and the acquisition of L&M in late Q2 of 2023, partially offset by lower North American railcar build.
Digital Intelligence sales were down 5.9% from last year, where we continue to experience lower revenues in our North American market, but we do see growth in our next-generation onboard locomotive products and digital mining.
Our services sales grew 17.3%. Services growth was driven by significantly higher year-over-year deliveries of mods, increased overhauls and parts sales. Our customers continue to recognize a superior performance, reliability and availability of our fleet. Across our Transit segment, sales increased 5.5%, behind growth in our products and services businesses. The momentum in the Transit segment remains positive as secular drivers such as urbanization and decarbonization accelerate the need for investments in sustainable infrastructure.
Now moving to Slide 10. Both GAAP and adjusted gross margin were up 2.4 percentage points during the quarter. In addition to higher sales, gross margin benefited from improved pricing and favorable mix between segments. Mix within the Freight segment was also favorable despite significantly higher new local and mod deliveries in the quarter.
During the quarter, we also benefited from favorable fixed cost absorption and benefits from Integration 2.0 as well as comparing against higher next-generation digital development costs in the first quarter of 2023. Our team continues to execute well to mitigate the impact of continued cost pressures by driving operational productivity and lean initiatives.
Turning to Slide 11. For the first quarter, GAAP operating margin was 16.5%, which was up 3.9 percentage points versus last year. Adjusted operating margin improved 3.4 percentage points to 19.8%. GAAP and adjusted SG&A expenses were down as a percentage of revenues as we leveraged higher sales with a strong focus on managing costs. Engineering expense was $48 million, modestly lower than Q1 last year. We continue to invest engineering resources and current business opportunities, but more importantly, we are investing in our future as an industry leader in decarbonization and digital technologies that improve our customers' productivity, capacity utilization and safety.
Now let's take a look at the segment results on Slide 12, starting with the Freight segment. As I already discussed, Freight segment sales were up 17.2% during the quarter. GAAP segment operating income was $368 million for an operating margin of 20.2%, up 5.7 percentage points versus last year. GAAP operating income includes $3 million of restructuring costs primarily related to Integration 2.0 and portfolio optimization costs. Adjusted operating income for the Freight segment was $439 million, up 48.3% versus the prior year. Adjusted operating margin in the Freight segment was 24.1%, up 5.1 percentage points from prior year.
The increase was driven by improved gross margin behind strong operational execution, favorable mix, improved pricing, Integration 2.0 savings and as we lap last year's investment in our next-generation digital development costs. At the same time, SG&A and engineering expenses were lower as a percentage of revenue. Finally, segment 12 month backlog was $5.67 billion, up 14.5% from the same period a year ago. The multi-year backlog was $17.9 billion down 2.3% from the prior year. Both our 12 month and multi-year backlogs demonstrate good visibility in '24 and beyond.
Turning to Slide 13. Transit segment sales were up 5.5% to $673 million. When adjusting for foreign currency, Transit sales were up 4.9%. GAAP operating income was $74 million, restructuring costs related to Integration 2.0 were $7 million in Q1. Adjusted segment operating income was $86 million. Adjusted operating margin as a percent of revenue was 12.7% and down 0.2 percentage points from last year, driven by unfavorable mix and higher input costs, partially offset by Integration 2.0 savings. Finally, Transit segment 12 month backlog for the quarter was $2.04 billion, up 3.3% versus a year ago. The multi-year backlog was also up 4.2% to $4.19 billion.
Now let's turn to our financial position on Slide 14. First quarter cash flow was $334 million. During the quarter, cash flow benefited from higher earnings, improved working capital and increased securitization funding. We continue to expect greater than 90% cash conversion for the full year. Our balance sheet and financial position continue to be strong, we ended the quarter with liquidity of $2.13 billion. And our net debt leverage ratio was 1.7 times at the end of the first quarter, which was favorable versus the same quarter a year ago at 2.3 times debt leverage. We continue to allocate capital in a disciplined and balanced way to maximize returns for our shareholders.
During the quarter, we repurchased $175 million of our shares and paid $36 million in dividends, which was recently increased by our Board of Directors, up 17.6% per share versus prior year.
With that, I'd like to turn the call back over to Rafael to talk about our 2024 financial guidance.