Learnings

Outcomes

Progress 18/19

This project is in the very early stages with an initial review phase of the GRAID robot underway to bring the project team together to begin the conceptual design to identify how the ART sensors could be incorporated on to the GRAID robotic platform. This will be the first time that the engineers at Halfwave have had a chance to see how GRAID was built and how the sensors can be connected to the body. 

The lab test which is an early deliverable for the project to understand if the ART sensors can operate with the coal tar enamel pipework that National Grid predominately have on its network is being organised and arranged. Halfwave already have a sample piece of the coal tar pipework which will be used for this test.

Progress 19/20

The project has progressed well during the year delivering the requirements of Phase 1 including a successful lab test of the sensors in CTE wrapped pipe which proves the capability of the technology. The Phase 1 Feasibility and Concept report was written and provided to National Grid for comment and approval. This document set out the high design of how the GRAID platform will look including the ART sensors.

Following Phase 1, the GRAID robot and associated support equipment was shipped to Halfwave in Bergen, Norway to allow the Halfwave project team to review and work with the robot throughout the remaining projects phases.

The next steps will be for Halfwave to start the Detailed Design work and order the long lead items ahead of the manufacturing stage. Dialogue between Halfwave and Synthotech will continue as the GRAID robot is modified and the design finalized.

Progress 20/21

Following the arrival of the GRAID robotic platform, trolley and launch vessel to the Halfwave office in Bergen, Norway the Detail Design activities were started. A full set of design drawings were shared with all project partners and National Grid for comment and confirmation. The designs detailed how the new ART sensors would be incorporated onto the existing GRAID robot body and how it would rotate to scan the full circumference. Full Bill of Materials were also produced allowing long lead items to be brought. During the detailed design stage, close communication with Synthotech was maintained to understand how the ART can be powered through the robot.

Once this report was completed and confirmed by National Grid the Build stage was officially started and the new rotating cradle at the front of GRAID was built. FAT followed as the motors operating all of the aspects of movement were tested in atmospheric conditions first. The robot was also introduced to the test rig at the Halfwave office for manoeuvrability testing. Once complete GRAID was fitted inside the launch vessel and taken to the pressure facility IKM near Bergen, Norway. Pressure was introduced to 70 bar(g) and function tests were carried out on the motors and the ability to take wall thickness readings on the launch vessel itself. Some issues were highlighted with noise and motors not performing in a pressurised environment, fixes have since been designed and are in the process of being fitted before GRAID is taken back to IKM for pressure testing. 

Following the agreed change control to extend the project to August 2021 the team will complete the FAT and then GRAID will be shipped back to the UK where Synthotech will carry out some specific repairs to the GRAID body and tracks before being sent to Spadeadam for offline testing in pressure.                                        

Closure 21/22                                                                                                                                                

The GRAID ART system was shipped to the UK, with the launcher system shipping directly to the offline test facility at RAF Spadeadam and the remainder delivered to Synthotech for repairs and upgrades.  At Synthotech, a number of repairs and upgrades took place, including cable re-terminations, umbilical cable replacement, cable dressing, etc. Once complete, the GRAID ART robot and associated equipment was taken to the Spadeadam test site, where it was installed and attached to the test rig, and the testing period commenced.   

Due to technical issues with both the GRAID robot system and ART motor system, less tests were completed 

than initially anticipated. Useful data and understanding of the systems capabilities and limitations were

gathered though. The test data also showed a noise spike, present at approximately 600 kHz, that had not been present before. This had an impact on the ability of the ART algorithms to correctly predict the wall thickness by imitating a resonance signal.     In September 2021, testing resumed at Spadeadam. The gimbal pitch motor was repaired, and function tested at atmospheric pressure successfully, but again encountered issues when exposed to pressure. This contributed to the poor-quality data recorded. There were a number of potential causes which were investigated further, including but not limited to:

·         Noise induced from ongoing nitrogen filling of the rig/launcher.

·         Newly released GRAID Control software has processed data where noise from the rotation motor is present.

·         Misalignment of the system has contributed to lower tail energy than required, coupled with the above noise, resulting in lower confidence measurements.

It was therefore decided to disable the umbilical management system (UMS) motor while scans were taken, which removed the above 600 kHz noise spike.                    

Following demobilisation of personnel from Spadeadam, Mekanisk Byraa (Mechanical Design Engineering) 

were contracted to investigate both the faulty and functioning motors to ascertain the cause of failure. Two 

main items were identified for improvement:

·         Improved oil flow by amending the internal bearing placement.

·         Reducing shaft friction by changing the simmer-ring to an O-ring and quad assembly.

These changes were implemented and both motors were subsequently pressure tested at 100 bar 

successfully, with the previous stalling issues no longer present. Following this the equipment was returned to the Bergen facilities so that the amended motors could be fitted and tested. The GRAID system was function tested at atmospheric pressure only. This proved that the system was functioning as far as possible prior to pressure testing the system. However, further issues were encountered with the system which needed to be rectified before testing could continue. These were addressed and suitable scans were taken and assessed to be sufficient to provide assurance the system was functioning as required.

In late February 2022, the equipment was mobilised to pressuretest facilities in Bergen. At this point the 

GRAID Cabin computer failed, showing signs of continuous system rebooting. Through communication with 

Synthotech, it was determined that the random access memory (RAM) was the likely cause of failure. Halfwave replaced this and have 

found the system now runs faster and smoother than seen previously. Acoustic scans were then taken at the pressure testing facilities. A scan was taken at 10 bar increments from 100 – 40 bar(g), using a nitrogen medium. In summary of these tests it was concluded that only in pressures above 80 bar nitrogen (approx. 70 bar natural gas) is the collected data acceptable for analysis of the wall thickness. Following these tests and before the project concluded all GRAID equipment was returned to National Grid Gas Transmission.

Lessons Learnt

Progress 18/19

To assist smoother contract negotiations on more complex legal agreements, earlier engagement within the process particularly around IP, liabilities and indemnities would aid a smoother and more efficient negotiation process.  

Progress 19/20

Increased focus on the complexities of the lab testing procedure and setup would have allowed for the testing to be completed in a shorter timeframe in future.

During the travel lockdown, due to the Coronavirus pandemic there was a requirement for the engineering teams at Halfwave and Synthotech to get together and discuss the GRAID robot in detail. As this could not be achieved face to face a virtual walkthrough of the CAD files was carried out instead and was very successful. This allowed for the deliverables to continue without causing delay to the schedule.

Progress 20/21

It was agreed that for a project of this magnitude with a large focus on the engineering side that more time should have been allocated to the build and FAT to cover any potential issues to be resolved. Continued virtual meetings through Teams has occurred which shows the potential for project partners to be outside of the UK.                                                                                                                                                                                                

Closure 21/22                                                                                                                                                            

The use of a shared Query Tracker document in the early stages of the project allowed questions and queries to be raised from either party, responses tracked and closed out as required.

During the assembly and manufacturing phase, Halfwave tested the assembled ART system at a pressure testing facility, to enable a thorough assessment of the ART systems capabilities. It was observed that the planned continuous rotation and acoustic pinging was severely impacted by acoustical noise. This noise appears to originate from various sources, but mainly from the rotation motor. Halfwave then resolved this by implementing a new stop/ping/start operational method. This including planning and execution of major software changes in 4 weeks to be ready for the mobilisation to the UK for Spadeadam testing.

MeTTL (Houston based supplier) selected as main supplier of machined mechanical parts. This allowed full project management of the raw material sourcing, machining, testing and delivery to be managed by one party. Due to the integrated nature of this work and close relationship with MeTTL, Halfwave were able to add additional manufacturing work scopes after the initial work scope award, whilst maintaining the same final delivery dates.

During pressure testing in Bergen, one of the yaw actuator motors failed. After investigation it was determined that a manufacturing error when potting and sealing the potentiometer caused a pressure build-up and eventual failure. This was immediately rectified by the manufacturer by replacing these units but had an impact on the schedule of 2-3 weeks before the parts were delivered and fitted. 

Returning the GRAID ART robot and associated equipment from Bergen, Norway to the UK was a difficult process. Delays were mainly associated with the importation into the UK of one spares box. Due to Halfwave having no legal entity in the UK, the decision was taken to import via one of Eddyfi’s (Halfwave/NDT Global parent company) other companies, TSC Subsea. Some delays can be attributed to uncertainty over who should import the equipment and complete the required import paperwork and payment of import fees and duties.