Good day, everyone. And welcome to Mobile Mini 2018 First Quarter Conference Call. At this time, I would like to inform you that this conference is being recorded and that all participants are currently in a listen-only mode. There is also a presentation that accompanies this conference call, which you can access at Mobile Mini's website at www.mobilemini.com. It is on the Investors page.
Before turning the call over to Erik Olsson, Mobile Mini's President and Chief Executive Officer, I will read the Safe Harbor statement. (Forward-Looking Cautionary Statements)
Now, I will turn the call over to Erik Olsson.
Good morning, everyone and welcome to Mobile Mini's first quarter 2018 conference call. I am Erik Olsson, Mobile Mini's President and CEO and with me is, Van Welch, our Executive Vice President and CFO. I will review the operational highlights of the quarter and the current business environment, and Van will discuss the Q1 financials. We will then open up the call to questions. And we encourage you to review the full quarterly deck proving more detailed results for your reference, which has been posted to our website as usual.
Now, let me begin by saying that I'm very, very pleased with our Q1 results, which were very strong for both our business segments, continuing the momentum built in the second half of 2017 and consistent with the strategy and initiatives that we have put in place over the last few years.
Tank & Pump Solutions had an outstanding quarter with rental revenues up $25.5 million, a 21.7% increase over Q1 2017. Q1 is typically the seasonally slowest quarter, but we kept the momentum from Q4 and we are now heading into spring and summer, which are traditionally the highest activity quarters for Tank & Pump and our pipeline looks very robust. Demand is strong across all geographies and our growth has been broad based in terms of (inaudible) segments.
Our strategy includes solidifying relationships with our large downstream customers. And in the Tank & Pump segment, just over 50% of our rental revenue is generated through our national accounts customers many of whom we have multiyear agreements with.
During the quarter, we singed new MSA with a large tank and pump customer to be the preferred provider. While we have previously conducted business with this customer, the new contract creates a more formal relationship and we expect to gain additional wallet share as a result.
In addition, we are beginning to see the incremental revenue related to the five new contracts we entered into in the second half of 2017, which we have reported on previously. And while the new contracts contributed nominally in Q1 2018, we expect the business to increase meaningfully over the remainder of the year.
Storage solutions rental revenues were up solid 11.5% in constant currency and we are particularly pleased with the 14.6% growth in North America, large national accounts have seen the value that are unique systems, national footprint and outstanding products and services offer.