Robbins provided four 6.5 m (21.4 ft) diameter EPBs with mixed ground cutterheads for two metro lines under construction. The two pairs of EPBs are excavating Line 3 Lot 11 and Line 10 Lot 5, for the China Railway Construction Corporation (CRCC) 13th Engineering Bureau and 23rd Engineering Bureau, respectively.

The two Robbins TBMs for Line 10 were launched in December 2011 and February 2012, while the Line 3 machines were launched in January and March of 2012. “Robbins is a special TBM manufacturer and the quality is good here.  We have used one Robbins TBM previously in Chengdu, and there was very good performance at the Metro Line 2,” said Li QuanShe, Nanjing Line 3 Project Manager for CRCC Bureau 23. At that previous Chengdu jobsite, a Robbins EPB achieved a project record of 129 m (423 ft) in one week through mixed ground.

Ground conditions on both Nanjing lines include soft soil, silty sand, manmade materials, small pebbles, and sandstone.  Shallow cover of 8 to 10 m (26 to 33 ft), a sensitive urban environment, and strict settlement requirements of less than 10 to 20 mm (0.4 to 0.8 in) are requiring customized excavation methods. “The earth is quite soft so we are keeping the thrust force very low (6,000 to 9,000 kN / 1.4 to 2.0 million lb). The operator is also employing continuous monitoring to maintain the proper alignment and earth pressure,” said Jason Xiao, Robbins Project Manager.  Foam additive will also be used to make the ground less sticky and reduce the required torque to excavate the material.

As of May 2012 the Line 10 EPBs have excavated over 600 m and 500 m (1,970 ft and 1,640 ft) of Line 10, respectively.  Advance rates are on the order of 40 mm (1.6 in) per minute, while settlement has stayed below the required limits.  At Line 3, the Robbins machines have excavated over 500 m and 100 m (1,640 m and 330 ft), respectively, with advances topping 60 mm (2.4 in) per minute.

Construction of the 40.2 km (25.0 mi) long Metro Line 3 and the 41.4 km (25.7 mi) long Metro Line 10 is well underway for owner Nanjing Metro Company.  The new subways are part of the municipal government’s extensive plans to improve access across the Yangtze River Basin with up to 17 rail routes totaling 600 km (370 mi) by 2030.

Join Robbins at Stand 202 to learn more about our recent tunneling advances. In the past year, Robbins opened its first South American-based office in Santiago, Chile. Staff from this location will be at the exposition, ready to talk to you about your upcoming project needs.

Epic Break Through

Crews at Peru’s Olmos Trans-Andean Tunnel surmounted difficult conditions, including more than 16,000 rock bursting events, using the McNally Support System – a novel ground support method using steel or wood slats. The Robbins 5.3 m (17.4 ft) TBM overcame extreme geology 2 km below to bore the second deepest tunnel in the world.

Visit Robbins during the show exhibition May 21 to 23 at stand J1-J2 to learn more about our recent advancements.  The stand will feature interactive iPads, and will be staffed by knowledgeable international employees.  To schedule a meeting with us prior to the show, please send us an email.

It’s Time to Advance

In 2012, the leading Robbins has further proven its Onsite First Time Assembly (OFTA) method, launching hard rock and EPB TBMs a full four to five months earlier than comparable shop assemblies. OFTA was recently completed or is ongoing on Robbins TBMs in India, Vietnam, Turkey, and more.

Robbins innovations run deep—from TBM launch to breakthrough.  In densely-populated Mexico City, three 8.93 m EPB TBMs were custom designed to withstand complex mixed ground conditions at the country’s longest wastewater tunnel.  Within the first six months, a Robbins EPB operating with continuous conveyors averaged twice the advance rates of a competitor’s machines in similar ground.  View our project video on the Robbins YouTube channel.

Featured Technical Sessions

Robbins technical sessions include oral presentations and posters, on topics ranging from hybrid EPB TBM design to hard rock TBM performance in one of the world’s longest tunnels.

Oral Presentations:

Monday May 21, 2012
Session: 1.3 Long and Deep Tunnels, 2:15 PM
System Efficiency in one of the World’s Longest TBM Tunnels
Presented by Jim Clark

Monday May 21, 2012
Session: 2.3 Advance and Innovation in Mechanized Tunneling, 4:00 PM
Hybrid TBM Design and Selection
Presented by Brad Grothen

Poster Sessions:

Tuesday May 22, 2012
Poster Session B: 9:30 – 10:00 AM
Development of Pressure Compensated Cutters for EPBs and Slurry TBMs in High Pressure Conditions
Author: Zachery Box

Tuesday May 22, 2012
Poster Session C: 3:00 – 3:30 PM
Record Production in Long and Deep Hard Rock TBM Tunneling
Author: Steve Chorley

The tunnel route took the Robbins machine to within meters of a 16th century church, active sewer lines, building foundations, and other structures.  Real-time settlement monitoring was rigorous throughout the project, and the crew was diligent in maintaining earth pressure during excavation. TBM elements including a two-liquid back-filling system with rapidly hardening cement also aided in settlement reduction.
“Settlement stayed within the limits of between 2 and 5 cm (0.8 to 2.0 in) throughout the bore,” said Ismail Benamar, ICA Tunnel Manager from the TBM launch through 2011.

The complexities of the densely urban project location have been a hallmark of the project from the start, when the machine underwent Onsite First Time Assembly (OFTA) from a shaft on a city street.  “OFTA has the benefit of no pre-assembly–everything was delivered directly to the site and assembled here.  The assembly went very smooth, and it was a little over three months before we started to turn the cutterhead and push the machine forward,” said Ron Jelinek, Robbins Field Service Technician.

The machine was launched from the small shaft in February 2010 and proceeded to break through into seven cut and cover station sites ranging from 150 to 190 m (490 to 620 ft) in length.  During each hole through, the machine underwent routine maintenance and was re-launched.  Despite the numerous intermediate stations and the time required to walk through each station, advance rates topped out at 135 m (443 ft) per week, and averaged 400 m (1,300 ft) per month.

Custom EPB features aided in the efficient excavation, and included a two-stage screw conveyor with an initial ribbon-type screw to allow the passage of boulders up to 800 mm (2.5 ft) in diameter.  Active articulation allowed the machine to negotiate tight curves down to 250 m (820 ft) in radius with no segment deformation.

Upon completion, the 25.4 km (15.8 mi) Line 12 of the Mexico City Metro is the longest in the system.  The Mexican Federal District predicts that the new line will carry an average of 367,000 passengers daily, making it the fourth busiest commuter rail route in the capital.

The 10.0 m (32.8 ft) Robbins machine, in addition to a 6.3 m (20.3 ft) diameter TBM that completed tunneling in 2011, excavated a 4.6 km (2.9 mi) rail tunnel and a 3.2 km (2.0 mi) service tunnel section, respectively.  A third road tunnel was also excavated by TBM.  The routes are located in complex geology including massive to completely fractured limestone with clay seams; sandstone; siltstone; breccias and conglomerates plus multiple fault zones.

“The Robbins TBMs have proven to be very reliable machines and thanks to the correct selection of these machines we were able to finish the tunnels on time. This was in spite of the fact that construction risks, as assessed by geologic testing, were extremely high,” said Vladimir Fedukin, Deputy Manager of project owner DCRC-Sochi.

Contractors OJSC Stroy-Trest and CSC Bamtunnelstroy, both divisions of SK Most, contracted Robbins for technical service and project consulting after a first attempted rebuild by a third party.  Both rebuilt Double Shields were repaired and modified by a crew of 15 from Robbins Field Service and Engineering departments.

The newly rebuilt Robbins TBMs were designed for the difficult conditions with low profile muck buckets and radial scoops for improved face stabilization.  The design also included replaceable bucket lips and injection ports, allowing foam additives to be used through the cutterhead for ground treatment.  These features enabled the machines to pass through numerous fault zones.

In May 2010, the 6.3 m (20.3 ft) machine was stopped after encountering a significant fault zone consisting of broken rock and running soft ground.   Field service personnel and crew successfully freed the machine by excavating a bypass tunnel around the TBM cutterhead.  Following the restart, a combination of continuous probe drilling and ground treatment with cement silicate and foam kept the machine moving forward.  Excavation with the 10.0 m (32.8 ft) machine was similarly aided by continuous probing and ground treatment.

“The third tunnel complex has been the most difficult because of the geological conditions. There were 27 fault zones consisting of unstable geology with the potential to provoke delays and stop the TBMs. In every one of these cases we had to come up with specific engineering solutions. The construction of the tunnels was closely followed not only by the government of the country, but also by the International Olympic Committee. We know of no analogous construction in the world,” said Michael Gutnikov of General Contractor OJSC Stroy-Trest.

The extensive infrastructure project for  DCRC-Sochi (a subsidiary of Russian Railways), provides road and railway routes between the small town of Adler on the Black Sea and the mountain resort of Alpika, with a scheduled completion date of June 2013.  The new lines will also connect to the M-27 highway, improving infrastructure in the region.

Project Overview

In 2012, the final of two Robbins Double Shield TBMs completed tunneling on schedule in Sochi, Russia in preparation for the host city’s 2014 Winter Olympic Games.  In addition to the construction of the new Olympic park, water supply lines, power stations and arenas, the resort city wants to make sure that transportation isn’t a problem for its visitors.  The transportation infrastructure project, commissioned by owner DCRC-Sochi, was divided into six complexes and will link road and railway routes between the small town of Adler on the Black Sea and the mountain resort of Alpika.  The new lines will also connect to the M-27 highway, which travels along the Mzymta River through a national forest preserve with 46 bridges and 12 tunnels.

The entire project consists of 48.2 km (30 mi) of new road and railway lines, with a strict completion deadline of June 2013.  In order to meet the schedule, excavation was performed in various ways, including using roadheaders, drill and blast equipment, and five TBMs.

Custom Rebuilds

Contractors OJSC Stroy-Trest and CSC Bamtunnelstroy ordered two refurbished TBMs to excavate parallel service and railway tunnels measuring 5.8 km (2.8 mi) and 4.6 km (2.9 mi), respectively.   The rebuilt machines were selected to construct the tunnels due to their fast procurement time compared to new machines and the aggressive deadline of the project.  A 10.0 m (32.8 ft) TBM was originally used on the Abdalajis rail tunnels in Spain between 2003 and 2006 and removed from storage for the Complex 3 tunnel.  A 6.2 m (23.3 ft) Double Shield was originally built in 1993 for a hydroelectric project in Switzerland, and has since been used on multiple tunneling projects, totaling over 45 km (28 mi).

The 10.0 m (32.8 ft) machine was supplied for the Sochi project as rebuilt by a sub-contracted supplier, but several problems at start-up unveiled that some of the machine’s major components needed to be refurbished or replaced.  After learning this, Bamtunnelstroy hired Robbins for on-site technical service and project consulting for Complex 3, as they were the original manufacturers of two of the three TBMs.

A crew of 15 from Robbins field service and engineering departments repaired and modified both TBMs.  The 10.0 m (32.8 ft) machine received a new cutterhead support from Italy, while the main bearing was refurbished at a factory in Germany.  In order to transport the 120 metric ton (264,554.7 lb) main bearing, the Antonov-225 aircraft was used, as it is the only one in existence that can carry loads up to 250 metric tons (551,155.7 lb).  The TBM also received upgrades to the lube system, cutterhead pressurization, and changes to the seal lubrication system.  The 6.2 m (23.3 ft) Double Shield received new gear boxes and a PLC system.  To make sure boring went smoothly, the Robbins crew stayed onsite until both machines were up and running.

Geology

The Robbins TBMs were specifically designed to excavate the fractured and faulted sedimentary geology that makes up the Sochi region.  After testing the soil, it was determined that the machines would be boring mostly massive to completely fractured limestone with clay seams.  Some sedimentary rock with sandstone and siltstone was also detected, as were fault zones made up of breccias and conglomerates.

Both machines were designed with a flat face, low profile muck buckets and radial scoops to optimize stabilization at the face of the tunnel.  They were also equipped with replaceable bucket lips and injection ports, which allow foam additives to be injected into the soil through the cutterhead to treat the ground before and during boring.

Tunnel Excavation

The 6.2 m (23.3 ft) TBM was launched in March 2010 in mixed ground.  In May, however, the machine was stopped after it came across a fault zone consisting of broken rock and running soft ground.  Field service crews were able to free the machine by hand excavating a timber bypass structure around the machine in front of the cutterhead, allowing debris to be removed.  To evaluate the ground ahead, the crew drilled up to 62 m (203.4 ft) in front of the machine and found that the geology consisted of highly fractured ground.  In order to accommodate the ground, polymer foam was injected in front of the machine to consolidate porphyry material around and in front of the cutterhead.  The TBM was able to move forward without a problem once this was completed.  To prevent a recurrence of the problem, crews performed continuous probe drilling during the remainder of the advance.  When necessary, the ground was treated with cement silicate and foam to keep the machine moving steadily forward.

Despite its challenges, the 6.2 m (23.3 ft) TBM experienced good advance rates of 100 to 120 m (328.1 ft to 393.7 ft) per week, and 14 m (46 ft) per day.  The machine achieved breakthrough at the service tunnel on March 2, 2011.  After completion, the machine was disassembled and is now being stored near the city of Novorossiysk.  It is expected to be used for future tunneling projects, as it is in good shape and experienced very low cutter wear during its bore on Complex 3.

The 10.0 m (32.8 ft) Double Shield was launched in September 2010 and excavated effectively through fault zones 25 and 50 m (82.0 and 164.0 ft) wide, consisting of highly weathered material have been excavated so far, using probe drilling and pre-grouting to consolidate the rock. The massive machine completed its excavation in 2012, breaking through on February 14.

The shotcrete is applied manually and consists of a continuous mixing and charging pump system, customized dry mortar mix with polypropylene fibers, and a fast-acting accelerator. The shotcrete, developed by MCM Co., Ltd. and DENKA of Japan, has been used on numerous hard rock TBM and NATM projects in Japan, though this is the first time the system has been used internationally.  “The dry mix system is advantageous because it can be started and stopped whenever necessary, and can be mounted in the TBM back-up.  Wet systems, by comparison, generate unused mortar if frequently started and stopped, requiring downtime for cleaning,” said Mr. Nobuo Suematsu, Marketing Director for MCM Co., Ltd.

MCM and DENKA worked with Robbins to create a near-zero rebound L1 shotcrete system to be used in the granitic hard rock of the tunnel, with rock strengths of up to 200 MPa (29,000 psi). The shotcrete is applied to the top 180 degrees of the tunnel following each TBM stroke in a 2 cm (0.8 in) layer directly behind the cutterhead support.  This layer is accompanied by ring beams depending on the ground conditions.  Compressive strength of more than 15 MPa (2,200 psi) is achieved within 24 hours of application.  “The shotcrete is very quick setting with no rebound, and the mortar does not require high pressure application,” said Mr.Yoshikuni Nakano, Deputy Project Manager for contractor SNUI JV (a consortium of Shimizu Corporation, Nishimatsu Construction, UEM Builders Bhd, and IJM Corp).

The shotcrete system has so far resulted in less downtime compared to conventional ground support, as the shotcrete can be applied during excavation.  In the somewhat fractured ground conditions currently being encountered, the machines would have required an estimated two hours of ground support work per excavated meter with conventional methods.  This would have added up to 210 days to excavate and support the ground. With the fiber mortar system this time has been reduced to 158 days—a time savings of 52 days.

With the three TBMs now between 4 and 6 km (3 and 4 mi) into their respective 11 km (6.8 mi) long sections, benefits such as dust reduction are also becoming clear. “The shotcrete offers environmental benefits, because it is transported in sealed cars without exposure to the surroundings,” said Andy Birch, Robbins Site Manager.  Bonding, according to Birch, has been good and rebound has been minimized compared with standard shotcrete mixtures.

The Pahang Selangor Raw Water Tunnel, for the Malaysian Ministry of Energy, Green Technology, and Water (KeTTHA), will transfer water from the Semantan River in Pahang State to the Selangor / Kuala Lumpur region, traveling as far as 1,200 m (3,900 ft) beneath the Titiwangsa mountain range in varying rock conditions with some ground water.  TBM excavation is expected to be complete in 2013.

Local contractor W.L. Hailey, now part of Layne Heavy Civil, utilized a variety of methods in different sections, including cut and cover and hand mining, as well as the shielded Rockhead. “This project is unique. Its challenges included rock excavation via trenching to conform to the project’s restrictions on controlled blasting.  Tunneling was done under 15 railroad tracks, and open cut pipe work was completed inside of the CSX Radnor rail yard with up to 1,000 tractor-trailers entering and exiting per day,” said Brian Rieschick, Project Manager for Layne Heavy Civil.

To complete the rail crossings using the Rockhead, crews conquered unexpectedly high volumes of water that flowed into the tunnel about 500 ft (150 m) into the bore during the summer of 2011. The water inflows, in limestone ranging from 8,000 to 12,000 psi (55 to 82 MPa) UCS, reached rates of 60 to 70 gallons (227 to 264 liters) per minute.  Though excavation rates slowed in this section, the contractor was successful in dewatering the tunnel using two submersible pumps.  “The machine did a pretty great job—it averaged 18 to 20 ft (5 to 6 m) per 10-hour shift for the 900 ft (275 m) run in dry conditions, and at least 20 ft (6 m) per shift on the 500 ft (150 m) run.  We lost some time in wet ground when locomotives hindered advance rates, but that could not have been helped,” said Rick Ryon, Tunnel Superintendent for Layne Heavy Civil.

After successful dewatering using the pumps, excavation continued utilizing two shifts.  One crew quickly mined ahead during the day, while a second crew installed the liner plate during the night.  The 16 inch (400 mm) plates were grouted in place using cement and water grout, mixed on site. This process of dual shifts allowed for much better production rates for both the mining crew and the liner plate crew, and brought daily averages to over 20 feet (6 m).

The Robbins Rockhead completed its first 900 ft (275 m) long drive in three months, holing through on September 14th, 2011 into the 36 ft (11 m) deep intermediate shaft.  After the first drive, the crew found almost no perceptible wear on the cutterhead.  From the second shaft, the tunnel took an approximate 90 degree turn and drove another 500 ft (150 m) to complete the second section on November 1, 2011. “We did both runs with the same set of cutters.  At the end there was only one worn cutter after 1,400 ft (427 m),” said Ryon.

At 6,900 ft (2,100 m) long, the Powell Avenue 36-inch Water Main transports finished water for drinking and residential use through the existing Powell Avenue Pumping Station.  The project is part of the Metropolitan Government of Nashville and Davidson County’s Master Water Growth Plan, providing a capacity increase of 10 million gallons (38 million liters) per day to support Nashville’s growing population.

Myth No. 1 – It will be a disaster if the parts don’t fit together on the job site!  That is why a full factory assembly is required.

This myth doesn’t take into account three factors:

1.  Partial assembly: Major sub-assemblies are pre-assembled in the factory.   The main bearing and seal assembly, for example, is fully factory assembled.  It is only the major parts that may not be pre-assembled.  However, in many cases, we pre-fit the pieces; forward shield to outer telescopic shield, outer to inner telescopic, inner telescopic to gripper shield, and so on for a double shield machine.   So the part fit-up is checked but the entire machine is not put together in the factory.

Major components are checked in the factory to ensure fit up.

2.  Modern measurement devices:  In those cases where it is not possible to pre-fit two pieces in the factory, we can use modern Coordinate Measuring Machines (CMMs) or “Laser Trackers” to take precise measurements of both pieces to insure fit up when they meet in the field.

A Robbins employee uses a CMM device in the Ohio manufacturing facility.

3.  In-field repairs:  When an offshore oil rig has a component failure do they disassemble it and take it to the mainland for repairs?  When repairs are required on hydroelectric turbines and generators, do they always take the big parts to a machine shop to repair?  No, they do not.  Many repairs of large scale equipment are made in situ, wherever the plant is located.  If it is discovered at the job site that a component has been mis-machined / manufactured it is most likely a minor error (remember the CMM measurements and component fit-ups in factory partial assembly) and repair can be effected on the piece in place at the job site.  In Robbins experience, this has always been the case and such repairs have been carried out when discovered on site and without impact to final startup schedule.

Myth No. 2 – The labor cost on an underground job site is far higher than labor cost in a factory.  It will cost far more money and time to assemble the machine on site for the first time.

OFTA Myth No. 2 leads to a wrong conclusion regarding cost, and fails to examine fully the potential benefits.

1.  Cost: This above statement is generally true; however, it does not necessarily follow from this statement that money will be saved by having a factory assembly plus a job site assembly.  Robbins history with in-factory and OFTA assembly reveals the following:

Traditional Factory Assembly

• Full factory assembly hours:  X hours
• On-site assembly of a fully factory assembled machine: 0.5X hours

OFTA Method

• Partial factory assembly for OFTA delivery: 0.5X hours
• OFTA site assembly of a partial factory assembled machine: 0.7X hours

Where the value of X is dependent upon the size and type of TBM as well as the complexity of the backup system.

If we assume that the cost of labor on the job site is twice the cost in the factory, then we can use $100/ hour for the job site and $50 / hour for the factory.  The total cost for the two methods is then:

• Traditional method cost = X hours ($50/hour) + 0.5X hours ($100/hour) = $100X
• OFTA method cost = 0.5X hours ($50/hour) + 0.7X hours ($100/hour) = $95X

In short, the total costs are nearly the same, or perhaps with some savings in favor of the OFTA method.

2.  Schedule: Another flaw with Myth No. 2 is that it does not consider a large potential benefit: the savings in schedule possible with the OFTA method.  By not completely assembling the TBM in the factory, it is possible to deliver a working TBM at the job site one to two and a half months earlier than with a traditional full-factory assembly and delivery.  This is a significant savings for most projects, when the site assembly can be done at this early stage.

OFTA for the 14.4 m diameter Niagara TBM was completed in four months, saving an estimated four to five months on the delivery schedule.

3.  Training of site personnel:  Another potential benefit that Myth No. 2 does not address is that of training.  The contractor’s site personnel who are involved with OFTA assembly and testing get far more training due to the additional hours spent on the assembly and testing, and the larger Robbins crew present to assist and advise.  Robbins’ experience indicates that contractors who opt for OFTA deliveries are frequently capable of taking over the full operation and maintenance of their new TBM much quicker than contractors who opt for a traditional delivery.   This is due to the much deeper knowledge the contractor’s personnel gain during the OFTA assembly and testing.

Site personnel take part in the assembly of a Double Shield TBM in India.

In summary, the question to be asked when making the decision to use OFTA or go for a traditional factory assembly is: What are the potential risks and what are the potential rewards?  One must examine all potentials of the OFTA scenario, pros and cons, to come to the correct solution.   I’m not claiming that an OFTA scenario is correct for every project.   For example, if the start of boring of the tunnel is not on the critical path for the project and the TBM is a smaller diameter unit, it might be advisable to allow a full factory assembly. That way, when the job site is finally ready for the machine, it can be assembled a bit quicker on site.  Again, if the start of boring is not on the critical path and the labor cost difference between job site and factory is larger (e.g., job site is in Finland, TBM factory is in China), then it could be that a full factory assembly can be justified on a cost only basis.  However, in nearly every case when the start of boring the tunnel is on the critical path, then the faster delivery possible by OFTA is clearly favorable.

The biggest impediment to more widespread use of OFTA is limited thinking: looking at the potential risks without looking at the potential rewards.  Tunneling itself is fraught with risk, yet contractors take on jobs everyday due to the potential rewards.  OFTA is deserving of a similar analysis.

About the Author

Joe Roby (B.S., Mechanical Engineering, University of Washington) has worked in the tunneling industry for more than 20 years. He started at The Robbins Company as a stress analyst specializing in finite element analysis of complex structures. Subsequently he was a member of the 19-inch cutter development team. For five years he was managing director of Robbins refurbished and leased TBM division. He has authored many technical papers for conferences and industry publications on subjects ranging from cutters to TBM assembly and rebuilding practices. Today he serves as Robbins’ Vice President – Production & Logistics.

“South America is one of the most promising future markets with many upcoming projects, strong competition and potential for manufacturing opportunities. Setting up an office in this region was important to us because a close and constant approach with our clients is essential in the Latin American market,” said Rolando Justa, Managing Director of Robbins South America. The subsidiary was established to augment the growing regional market and provide project management services, TBM field service, sales functions and technical support to our clients. The office will work closely with the Robbins main offices in the United States as well as our offices in Spain and Latin America.

Robbins has 14 offices worldwide with more growth planned for the future, each providing support for local projects and growing markets.  “The benefit of having local support is immeasurable – customers will have an immediate response to field service issues, a conduit for our worldwide resources, and Robbins employees with whom they can communicate directly in their native language,” said Doug Harding, Robbins Vice President of Sales-Solon, Ohio.

Robbins South America Contact Information:

Robbins South America
Avd 11 de Septiembre 1881
Oficina 1515
Providencia, Santiago de Chile
Chile
Phone: +56 9 61353776
Email: justar@robbinstbm.com