Tifft Water Supply Symposium SEPTEMBER 21-22, 2016 BUFFALO, NEW YORK Impossible Journey: Underwater Inspection of Large Diameter Water Transmission Tunnel Kristin Wheaton, PE Jim Clark Bob Clarke, P.Eng, PMP Vasyl Kravchyk
New York City Water Supply System
Rondout-West Branch Tunnel
Inspection Goals Gather information to evaluate needs for tunnel repair and risk of tunnel failure Basic Goals: Visual assessment Locate leaking areas Identify cracks
Choosing the Right Tool for the Job Autonomous Underwater Vehicle (AUV) Remote Operated Vehicle (ROV) Conventional Manned Inspection
AUV Tunnel Inspection
ULIISYS AUV Basis of Design Propeller Strobes ADCP Hydrophone Pressure Sensor Cameras Launch Guide Rail Acoustic Transponder Back Scatter Sensor
ULIISYS AUV Development
AUV Insertion for Launch
ULIISYS AUV Image Filmstrip
Evaluation of ULIISYS AUV Images Tunnel Flow
ULIISYS AUV Inspection Results 12
Updated: Goals for ROV Inspection Basic Program Improved visual assessment in areas of interest Detect specific leaks Measure specific cracks Enhanced Program Crack depth Void detection Core samples to confirm voids and liner condition
Next Step: Inspection with ROV
ROV Program Implementation Full Capability ROV 16 mile tether Site-Specific ROV: Roseton Hybrid AUV/ROV launched from Shaft 8 (13 miles away), plug in at Shaft 5A Articulating ROV launched through Shaft 5A around 48 needle valve (3.5 miles away) Wawarsing Area Conventional ROV launched from Shaft 2A (4.5 miles away) Cost-prohibitive J.F. White ASI Group
Roseton Area Chiton ROV
Roseton Area Chiton ROV Riser Valve
Roseton Area - Shaft 5A Riser Valve 12 annular clearance through valve Annulus obstructed by tripods Construct full-scale valve model Fabricate 30 man-basket Develop special work-under tooling
Roseton Area Chiton ROV Support Systems
Roseton Area Chiton ROV
Roseton Area Chiton ROV Testing
Wawarsing Area Mohican ROV
Wawarsing Area Mohican ROV Requirements Real-time feedback required for immediate inspection of features of interest (cracks, spot anomalies) Provide multiple cameras and sensors for close examination of cracks Determine if those features leaked Accurately identify and log the position of the ROV at all times
Wawarsing Area Mohican ROV ASI Mohican ROV has been modified specifically for the inspection of long flooded tunnels OVERVIEW High bandwidth capacity to support multiple sensor configurations 6 mile excursion capability Unlimited duration of inspections since power supply is through umbilical to surface Imaging sonar for navigation, profile sonar for crosssectional measurements SPECIFIC TO PROJECT 4 IP video cameras (5MP), 2 SD video cameras (0.35 and 0.48 MP standard video) Magnetometer Dye pump and telltales for leak detection Inertial navigation system Rotary brush for spot cleaning liner Calibrated standoff fixture for feature measurement Additional lighting for HD cameras Depth probe for crack depth measurement
Wawarsing Area Mohican ROV Launch location Shaft 2A 1,560 feet down to tunnel 600 foot air gap 14 foot diameter access shaft Potable water supply Buried access
Wawarsing Area Mohican ROV Record all data in a synchronous and correlated manner
Wawarsing Area Mohican ROV TRACK PLOT FROM INS FORWARD SD CAMERA FORWARD HD CAMERA ROTARY BRUSH DYE INJECTION FILE MANAGEMENT CAMERA SET-UP INS ST`ATUS CPU STATUS NAVIGATION SONAR DEPTH PROBE NOTES PROFILE SONAR AUX POD CONTROL CRACK WIDTH MEASUREMENT REAR FACING
Wawarsing Area Mohican ROV
Wawarsing Area Mohican ROV INVERT FEATURE
Wawarsing Area Mohican ROV
Wawarsing Area Mohican ROV
Latest AUV Deliverable
Latest AUV Deliverable
Latest AUV Deliverable
Latest AUV Deliverable
Latest AUV Deliverable
Enhanced Tools R&D
Underwater Laser Scanner Development Shop tests using underwater laser scanner for high resolution measurements 2 x2 concrete slabs placed on 6.75 curved template, some intact, some cracked
Underwater Laser Scanner Development Produced high density point clouds with measureable cracks But there were also artifacts in the data that could be misinterpreted as features
Underwater GPR Development Ground Penetrating Radar (GPR) was investigated as a means of checking for voids in behind the liner Tests were done on a variety of concrete/rock test slabs in the dry and then wet
GPR Trailing Antennae Development Recording 2 Antennae ROV Prototype underwater GPR antennae successfully testing on known concrete discrepancies of lock structure on the River Cam in 2009.
Underwater GPR Development Results indicated the interface between concrete and rock as well as the engineered voids, requiring expert interpretation Verification of the interpretation requires destructive testing (core drilling) through the liner, which then would have to be sealed.
Development of Underwater Ultrasonic Crack Measurement Ultrasonic application for determining crack depth, liner thickness and voids Tests conducted dry and wet for comparison
Development of Underwater Ultrasonic Crack Measurement Crack depth comparable results for dry and wet Liner thickness comparable results for dry and wet
Thank You Kristin Wheaton, PE kristin.wheaton@arcadis.com 201.398.4387 Jim Clark jfreemanclark@gmail.com 978.549.6603 Bob Clarke, P.Eng, PMP bclarke@asi-group.com 905.641.0941 x 241 Bill Sherwood bsherwood@asi-group.com 905.641.0941 x 234