Packaged for the Rental Market
 click to enlarge Image 1: Grove's RT890E |
September 1, 2004 - The Grove brand name is practically synonymous with rough-terrain cranes; the company has been building them since the 1960s. In the fall of 2003, Grove released its newest addition to that long heritage. More significant is that the RT890E is the first all-new crane to be introduced by the company since the brand was acquired by the Manitowoc Crane Group (MCG) of Manitowoc, Wis.
The 90-ton RT890E will soon be joined by the 75-ton RT875E. These two units share commonality of components and utilize the same chassis. They will be entering a fairly strong market segment, meeting direct competition from Tadano's TR800XXL, Terex's RT775, RT780, and RT1000 and Link-Belt's RTC8070 and RTC 80100. But Grove is confident that the RT890E and RT875E offer North American buyers exactly what they're looking for in an RT crane package. Part One of a two-part series follows on Grove's RT890E. Watch the next issue of Lift and Access 360 for a hands-on evaluation of the crane.
Top concern: Transportability
 click to enlarge Image 2: The RT890E on display at last fall's Product Expo in Shady Grove, Pa. |
The North American market consumes 90% of Grove's RT crane production and the RT890E was designed according to the specific demands of that customer base. Product development was done in partnership with some of the company's dealers. Also influencing the crane's design was the reality that a majority of RT cranes end up in rental fleets with transportability being identified as a key concern among rental buyers.
Keeping the crane's weight to less than 95,000 pounds was a top priority. When the counterweight and the offset are removed, the crane's weight is trimmed to well under this target, achieving a transport weight of 90,858 pounds.
An on-board hydraulic lifting system is standard to assist with removing the 22,000-pound one-piece counterweight. According to the company, it takes three people to remove the counterweight. Hydraulic controls, located on either side of the super structure, release the massive holding pins. From this position, an operator can also lower or raise the counterweight into position. In order to eliminate as much weight as possible, the counterweight's lifting mechanism is self-contained. The auxiliary winch is integral to the counterweight. Quick disconnects for the hydraulic lines are used to facilitate a speedy detachment process.
Buyers also asked that the wheelbase not exceed 28 feet. At 28'9", the RT890E comes pretty darn close to that compact size for a crane of this capacity. The only previous Grove product close to this class, the discontinued RT9100, was about 30 ft long. Finally, there was the issue of maximum stowed height. Customers asked for a low 12'6" and Grove delivered a unit with two inches to spare. The RT890E comes in at 12'4". Key to achieving this was the placement of the engine. It is nestled low inside the chassis allowing the turntable to be lowered and thereby reducing the height of the superstructure.
New vendor philosophy
 click to enlarge Image 3: Primary and auxiliary hoists are now supplied by Braden Winch. |
Under MCG's management, one of many manufacturing changes being made is a shift to outsourcing more components. A prime example is the replacement of Grove's own winch to a Braden winch supplied by the PACCAR Winch Division, Broken Arrow , Okla. The winch is designed by Grove and built to the company's specifications by Braden. Unlike the Grove winch used previously, the Braden winch utilizes a smoother performing axial piston pump.
The primary and optional auxiliary hoists feature two-speed power up and power down with an automatic multi-disc brake. Both hoists are positioned so that inspections are easy to do from the crane's deck, provided by full-size fenders on either side of the machine. The main hoist is reeved with 3/4" (19 mm) Wireco 6X37 class rotation-resistant wire rope. Maximum line length is 600 feet and maximum line speed is 514 fpm. The auxiliary hoist uses rotation-resistant Flex X 35 wire rope. Maximum line pull is 16,800 pounds.
Meanwhile, however, the company is also making moves to limit the total number of outside vendors. The entire hydraulic system, for example, is now sourced by a single company. Parker, Mayfield Heights , Ohio , now provides the pump, valves, and hoses for the entire machine. Of note is the Parker variable displacement piston pump providing hydraulic pressure to operate all the boom functions. This configuration is a first for Grove, and according to Grove Product Specialist Paul Cutchall, is not common in the industry. Variable flow translates to a smoother operating hydraulic system. The pump works in tandem with a Parker gear pump to power steering and outriggers. Combined, the two pumps produce 133 GPM (503 LPM) at 4,000 psi (277.7 bar).
 click to enlarge Image 4: Watch next issue of Lift and Access 360 for my hands-on evaluation of the RT890E. |
The RT530E, introduced in 1999, was the first in the E series. Market acceptance of it and subsequent products led to the development of the RT890E, the largest crane yet in the E series. Although the E signifies membership in the specific generation of Grove RT crane, E has also come to denote its key characteristics. E is also for Easy (to produce and maintain), which is the likely reason Grove dealers have already lined up in support with multiple orders for this product. Although Grove does not discuss lead times with the media, every indication leads me to the conclusion that the company's order book on the RT890E is nice and fat.
