Concept · in development

Pipe-spool verification · concept in development

What is TRAMMEL?

TRAMMEL is a spool-verification tool in development. The idea: fit a measuring head at each end of a fabricated pipe spool, compare where the ends are with where the drawing puts them, and report the difference separately in Northing, Easting and Elevation.

Follow the development See how it works
Compares
Drawing → measured → difference
Reports
N, E and EL, each on its own
Stage
Concept, in development
Concept visualization of a TRAMMEL measuring head: a round brushed-metal body with a black knurled dial, a centre faceplate marked TRAMMEL and A, and four adjustable arms with engraved scales.
Fig. 1 · Concept visualization, not a photograph of finished hardware

How it works

From the drawing to the difference, one axis at a time.

A pipe spool is built in a shop to a drawing, then installed where it has to meet the rest of the plant. Follow one spool from head A to head B.

Concept visualization: a fabricated pipe spool on stands in a fabrication shop. A TRAMMEL head is fitted at each end, HEAD A on a high support and HEAD B near the floor. Drawn dimensions show a 4000 mm run, a 5000 mm drop and a 3000 mm run between them.
Drawing (reference) Measured Concept visualization · illustrative values

  1. Start from the drawing

    The spool drawing fixes a reference coordinate for each end: Northing, Easting and Elevation, in plant coordinates. In this illustration, end A’s reference is:

    End A reference coordinate, millimetres: N 12000.0E 20000.0EL 5600.0

  2. A head at each end

    In the concept, a TRAMMEL head fits at each open end of the spool: HEAD A and HEAD B. Those are the two ends that will have to connect in the field.

  3. Follow the geometry

    Between the heads, the route breaks into straight legs along plant axes: 4000 east, 5000 down, 3000 south. Added up, they put end B’s reference at:

    End B reference coordinate, millimetres: N 9000.0E 24000.0EL 600.0

    N 12000 − 3000 · E 20000 + 4000 · EL 5600 − 5000

    Isometric schematic of the illustrated spool. From end A the route runs 4000 millimetres east, drops 5000 millimetres and runs 3000 millimetres south to end B. Axis arrows show north up-left, east up-right and elevation up. An enlarged detail at end B shows the measured point offset from the drawing point by plus 3.0 east, minus 1.5 north and minus 2.0 elevation.
    Isometric schematic, not to scale. Illustrative values.

  4. Compare, axis by axis

    End B’s measured position is set beside its reference. The difference is reported for each axis on its own. One combined distance would hide which way the end is off, so it never stands in for the three.

    End B · drawing → measured → difference Illustrative values, mm
    Axis Drawing reference Measured Difference measured − ref.
    NNorthing 9000.0 8998.5 −1.5
    EEasting 24000.0 24003.0 +3.0
    ELElevation 600.0 598.0 −2.0

    Sign convention for this illustration: difference = measured − reference. Positive N is north of the drawing position, positive E is east, positive EL is higher. End A is taken at its drawing position.

    These values were chosen for this illustration. They are not measurements, and not an accuracy or tolerance figure.

For newcomers

Terms used here

Spool
A prefabricated assembly of pipe, fittings and flanges, built in a shop to a drawing and installed in the field.
Reference coordinate
Where the drawing places a point, in plant coordinates.
Measured coordinate
Where that point is found on the built spool.
N · E
Northing and Easting: horizontal plant coordinates, increasing toward plant north and plant east.
EL
Elevation: height, increasing upward.
Difference
Measured minus reference, for each axis. Its sign gives the direction.

Status

What this page claims, and what it doesn’t

Stage
In development.
Images
Concept visualizations. Not photographs of finished hardware, and not specifications.
Numbers
Illustrative, chosen to show the arithmetic. Not measurements.
Accuracy, tolerance
None claimed.
Measuring method
Not described on this page.
Working record
Kept in the development section.

Development

Follow the development

This page is the introduction. The development section holds TRAMMEL’s working record.

Open the development section trammel.ca/development/

Contact

Start a conversation

For questions, introductions or a conversation about spool verification, write to:

scott@trammel.ca