Hitachi upped its versatility with a trio of "ultrashort tail-swing" excavators at ConExpo-Con: the ZX135US-7, ZX245USLC-7 and the ZX345USLC-7. The new machines are designed to fit comfortably on tight jobsites while providing plenty of power to get the job done.

The ZX135US-7 excavator weighs in at 31,973 pounds, has a 19-foot 7-inch maximum dig depth, and a bucket breakout force of 23,380 pounds.

The 56,669-pound ZX245USLC-7 excavator offers a maximum dig depth of 21 feet 8 inches and a bucket breakout force of 35,520 pounds.

The largest of the three, the ZX345USLC-7, has a 76,955-pound operating weight, digs to a depth of 24 feet 10 inches and has a bucket breakout force of 45,411 pounds.

As the number of urban projects continues to increase, there is clear demand among operators for larger reduced-tail-swing excavators. These excavators can work in congested areas while keeping lanes open on road projects, said Patrick Baker, product manager, medium and large excavators, Hitachi Construction Machinery Americas Inc.

All three models are powered by Isuzu engines, producing 100 net horsepower for the ZX135US7, 164 net horsepower for the ZX245USLC-7 and 249 net horsepower for the ZX345USLC-7. Three different power modes “ economy, power and high-performance “ best match available power to the working conditions. An auto-idle system with auto-shutdown control conserves fuel.

Hydraulic systems have been matched to the machine size for optimal performance while reducing fuel consumption, Hitachi says. HIOS IV technology on the ZX135US-7 ensures a responsive boom, arm and bucket, while the ZX345USLC-7 relies on TRIAS II technology that makes efficient use of available power. The ZX245USLC-7 uses next-generation TRIAS III technology for rapid response to all control inputs while minimizing energy loss throughout the system.

Hitachi's clear dominance and clear ownership of the hydraulic excavator market is built upon the hydraulics, said Simon Wilson, Vice President, Sales. Our new TRIAS pumps ” three pumps on a lot of our construction-size machines allow the operators [to perform] multiple different functions at the same time without having to lose any of performance by one to the other. Or on our large-size machines, the HIOS IV and HIOS V systems are new improvements in these hydraulic systems.

A new roll-in metering control valve on the ZX245USLC-7 allows hydraulic pump power to be reduced when the arm is operated with a low load. When digging, the roll-in metering control valve reduces hydraulic-pressure loss to the tank, decreasing the pump power needed for digging operations and improving fuel efficiency.

On the ZX245USLC-7 and ZX345USLC-7, the attachment/arm priority can be adjusted on the monitor to match the attachment or the operators preference. The operator can dictate whether the speed of the attachment or the arm should be prioritised, as well as adjust the boom-raise priority. This dials in the machine for everything from truck loading to heavy digging.

The larger cabs feature increased head clearance, an adjustable air suspension seat, an 8-inch anti-glare LCD monitor, Bluetooth radio and low-effort pilot controls. Thicker glass on the rear of the cab decreases noise, while improved airtightness keeps the dust-out, and cab mounts reduce the vibration when traveling.

Along with a comfortable operator environment, the Aerial Angle peripheral camera system gives a 270-degree birds-eye view of the machines surroundings. A rear-view camera allows the operator to see the area right below the counterweight, and LED lights provide visibility in challenging conditions.

The ZAXIS-7 excavators have been outfitted with a more durable undercarriage and boom. Hitachi says the lower roller design on the undercarriage helps prevent mud compaction, protecting oil seals. The upper and lower rollers also feature improved idler sealing. On the boom, the bushings are installed in the brackets at the boom end and the boom foot for durability.