Metrology Stab and Receptacle
LBL transponder accessory
Engineered for: Structure
Designed for use with Compatt 6 and Gyro Compatt 6 (including plus variants), the metrology stab and receptacle enables LBL transponders to precisely and repeatedly installed on subsea structures.
At a glance
Allows you to accurately align transponders on structures
Perfect for installation during metrology campaigns
Allows transponders to be quickly removed and re-installed using ROV
Two stab variants available to bolt onto either Inclinometer Compatts or Gyro Compatts
Can be fitted on the back deck using existing hole patterns
Tell-tale indicator confirms the stab is fully docked into the receptacle
Designed for precision survey and construction
Want to know more?
With a high manufacturing tolerance combined with a pop-up ‘tell-tale’ flag that provides visual confirmation the transponder is precisely docked, our stab and receptacle saves times and improves the accuracy of subsea construction.
Using our stab and receptacle, the traditional method of rotating of a stab in a hub during metrology operations to determine stab-to-receptacle slop, can be eliminated. With this time consuming task removed, acoustic metrologies have the potential to be completed in less than six hours.
The tolerance of the design allows for 0.1° for heading and 0.01° for pitch/roll which is the same quoted error of a calibrated Gyro Compatt 6. This improves the results of the metrology or other positioning tasks and reduces the need for error determination of the stab/receptacle.
The receptacle is designed to bolt into the eight bolt hole pattern of the industry standard 8” AWWA Class D flange. This allows the user to either bolt this flange onto the structure or to provide bolt holes in the structure itself. After dimensional control techniques to determine the relationship of the bolt holes in relation to the structure points of interest (jumper hubs, CRP, spool flanges, etc), the receptacle can be bolted in with known offsets to these points. This allows fast and precise inferred metrology to one or multiple hubs or flanges from a single Receptacle.
The receptacle features a 45° cone in which the stab sits. This reduces the possibility of debris building up on the interface between the two and allows for a more precise connection due to the point of contact being exactly circular regardless of any small expansion /contraction effects.
The stab also features an alignment bar rather than alignment pins to aid docking and provide superior heading alignment. An O-ring on the stab shaft assists in ensuring the two are precisely mated.
Metrology Stab and Receptacle case studies
Rewriting the subsea survey rules
Fusion 2 is not just simplifying offshore survey operations, it’s changing how people operate – for the better. Mike Clark, Global Survey Manager, i-Tech 7, told Baseline about their route to demonstrating reductions in offshore vessel schedules for Subsea 7’s deepwater field development projects using the real-time SLAM capability in Fusion 2.
Client: i-Tech 7
|Feature||Receptacle Type 8300-250||Stab Type 8300-240||Stab Type 8144-150|
|Compatible Products||Stab 8300-240 & 8144-150||Inclinometer Compatt5 & 6||GyroCompatt6|
|Outside Diameter||343 mm||185 mm||185 mm|
|Maximum Height||100 mm||164 mm||76 mm|
|Stab face to Flange Face||76 mm||76 mm||76 mm|
|Mechanical Construction||Acetal (Delrin)||Super duplex stainless steel||Super duplex stainless steel|
|Bolt Hole PCD||Removable||n/a||n/a|
|Attitude Tolerance||Heading 0.1°, Pitch / Roll 0.01°||Heading 0.1°, Pitch / Roll 0.01°||Heading 0.1°, Pitch / Roll 0.01°|
|Alignment Quadrants||Four (0°, 90°, 180°, 270°)||Four (0°, 90°, 180°, 270°)||Four (0°, 90°, 180°, 270°)|