LOAD & HAUL UNDERGROUND seconds , the LHD delivers 52 % quicker acceleration and achieves a 7 % higher speed on grade .
The Cat 2900 XE LHD has a higher , 18.5-t ( 20.4-ton ) payload for faster load cycle times than the R2900G to offer a 3- to 4-pass match to the 63-t ( 70.5-ton ) Cat AD63 underground mining truck . Both models offer a variety of capacity options to match mine site conditions . Productivity for the R2900 XE is approximately 20 % higher compared to its predecessor .
The R2900 XE shares many parts and components with the previous R2900G model and the industry proven Cat 988 XE large wheel loader . Many of the safety and technology advancements are also shared with many other models from the broad range of Cat equipment , allowing the local dealer to continue to provide support , service and parts to the new R2900 XE . In 2022 , Caterpillar conducted a six-month field follow of the new R2900 XE , which followed the unit over 1,500 operating hours . It was compared to the mine site ’ s existing fleet of five R2900G units . The R2900 XE was equipped with an 18.5-t ( 20.7-ton ) rated bucket , and the R2900Gs were equipped with 17.2-t ( 19.3-ton ) rated buckets .
Data showed a 34 % average fuel consumption reduction with the R2900 XE , primarily due to the R2900 XE ’ s SR electric drive system and hydraulic piston pumps . The new R2900 XE also offered 54.9 % lower CO emissions at high idle , while NOx emissions were 34 % and 42.1 % lower at idle and high idle , respectively . Diesel particulate matter was lowered by 99.99 %, comparing the R2900 XE EU Stage V / U . S . EPA Tier 4 Final engine to the Tier 2 of the R2900G .
“ The data demonstrated the R2900 XE offers an improved working environment for all personnel at the mine ,” offers Caterpillar Product Applications Specialist – HRV Products , Gordon Wilkin . “ In addition to lower exhaust emissions , we observed a 7˚ to 11˚C ( 44.6˚ to 51.8˚ F ) reduction in working area temperatures . The R2900 XE operates quieter and reduces exposure to vibration levels compared to the R2900G .”
The new R2900 XE offers an impressive reduction in tyre wear , which Caterpillar attributes to the new traction control system design . Traction control reduces tire spin in difficult underfoot conditions to improve productivity , increase tyre life and reduce consumable costs . “ We have a machine that now has approximately 2,800 operating hours , and it hasn ’ t worn out a tyre yet . This is an impressive outcome and a large improvement over the previous model ,” adds Wilkin .
With its higher bucket capacity , the R2900 XE was expected to offer an increase in productivity , and it delivered . The R2900 XE provided a 101.6 % increase in tonnes / hour productivity on a duty cycle pulling material from the same loading
source to destination . The field follow results also demonstrated a 20 % increase in lift capacity over the R2900Gs , and the R2900 XE delivered 3- pass loading – compared to the R2900G ’ s 4- passes – of the mine ’ s AD60 and AD63 trucks , equipped with the mine ’ s preferred body size .
The operators at the mine gave the R2900 XE high remarks in Caterpillar ’ s operator acceptance survey , conducted at the field follow conclusion . All measured user impact statistics provided positive feedback with the highest accolades going to the HVAC system , ergonomics , noise , and safety features .
Production performance studies
At an Australian underground mine , Caterpillar evaluated the performance of the R2900 XE against the Cat R3000H . The performance and payload study included the same draw points measured in the field follow for each loader , and material was dumped at the same tipping location at the mine ’ s underground crusher .
The R3000H offers a rated payload of 20 t ( 22.0 tons ), the largest LHD in the Cat line , and was equipped with a 10.5 m 3 ( 13.7 yd 3 ) bucket . The smaller R2900 XE ’ s rating is 18.5 t ( 20.4 tons ), and it was fitted with a Cat 9.2 m 3 ( 12 yd 3 ) bucket for the study .
Throughout the study , the average payload for the R3000H was 16.9 t ( 18.6 tons ), while the R2900 XE recorded an impressive 16.8-t ( 18.5- ton ) average payload over the observed hauls . Even with the smaller bucket and rated payload , the R2900 XE outperformed the larger loader , “ as expected ,” adds Wilkin .
The R2900 XE was 15 % faster to fill the bucket , in just 11 seconds , and delivered faster cycle times , clocking a much faster fully loaded acceleration speed with its electric drive system compared to the R3000H . Compiling data from the draw points using the documented cycle times and payloads , Caterpillar calculated the R2900 XE ’ s capable productivity at 526.6 t / hour ( 580.5 tons / hour ) and the R3000H at 506.3 t / hour ( 558.1 tons / hour ).
Beyond offering higher productivity , the R2900 XE burned 13 % less fuel than the R3000H over the same application . This equated to a 12 % better tonnes / liter of fuel productivity result .
The mine site plans to equip the R2900 XE with a 9.8 m 3 ( 12.8 yd 3 ) bucket , which could increase average payload from 16.82 t ( 18.54 tons ) to 17.92 t ( 19.75 tons ). Additionally , the mine could realise a potential 6 % increase in productivity gains compared to using the 9.2 m 3 ( 12 yd 3 ) bucket .
A third study in Australia set the R2900 XE against a competitive LHD model with a published rated payload just over 17 t ( 18.7 tons ). The objective was to clear the same amount of material from the same specified area .
The R2900 XE cleared the area in 20 buckets compared to the competitive LHD ’ s 24 buckets , was 17 % faster in clearing the development and loaded the haul trucks faster . Plus , the measured operating heat generated by the R2900 XE was 7.1˚C ( 44.8˚ F ) lower on level ground and 11˚C ( 51.8˚ F ) lower on the decline than the competitive LHD .
In comparative working conditions , the R2900 XE had an 8 % lower fuel burn rate than the competitive LHD , saving on fuel costs . The R2900 XE also delivered a 20 % faster average cycle time on level ground and a 23 % average cycle time advantage when travelling down the decline
JUNE 2023 | International Mining 29