Neometrix / Structural & Load Testing Facilities / Transmission Tower Testing Facility / NMX-TTF-21

NMX-TTF-21 · ENGINEERED-TO-ORDER CLASS — FULL-SCALE TOWER LOAD TESTING · SERVO WINCHES · PLC CONTROL

Prove the tower on the ground, not on the line.

Name: Transmission Tower Testing Facility
SKU: NMX-TTF-21

A new tower design is calculated member by member. But only a full-scale test shows how the joints, bolts and members behave together, and a fault found on the ground costs a drawing change. Found on the line, it costs a circuit.

So the tower is stood on a rigid test bed and pulled by servo-controlled winches, at every cross-arm at once, in the ratio the load case sets, while the loads and the movement are recorded.

Discuss a tower test facility Capability note (PDF)

A full-scale transmission tower test station: a bare lattice steel tower with three cross-arms stands on a concrete test pad between two tall reinforced-concrete reaction walls, with steel test ropes running from the cross-arm tips down to pulley blocks at the foot of the walls, and a control building beyond a low rail

Fig · 01 — A tower test station: the tower on its test pad, a rope from every cross-arm to a reaction wall, and the control building outside the exclusion zone — illustrative render.

The article

a whole towera full-scale prototype

The loads

in stepmany points, one set ratio

The drives

servo winchesropes, pulleys, load cells

The control

a PLCclosed on the load cells

Status

engineered to orderno delivered unit claimed

ISO 9001ISO 14001Servo-controlled winchesPLC control & data acquisitionLoad-cell measurement

Overview

Why a whole tower is pulled, and not only calculated.

Because a tower fails at its connections as often as in its members, and calculation sees the members best.

Fig · 02 — The load path, drawn as a control loop: the plan goes down to the winches, and the load cells and the movement come back up.

A calculation says what the tower should do. The test bed says what it did.

What the facility is actually for

A transmission tower is a steel lattice built from hundreds of members and bolted joints. Each is checked on paper, but the way they share load is only proven by loading the whole structure.

The facility stands one prototype tower on a test bed and loads it through the same cases the line will meet: wind across the line, a conductor pulled along it, and weight from above.

Why the loads must rise together

A tower carries wires at several cross-arms. In a real gust they load together, in a fixed ratio. If one arm is pulled ahead of the others, the test loads the tower in a way the line never will.

So the loads are raised in step. Every point climbs toward its target at the same relative pace, and stops at the same hold.

Why the ropes are the hard part

A rope pulls in the direction it lies. When the tower leans, the rope angle changes, and so does the direction of the load on the tower.

The control must therefore watch the rope angle as well as the force, and keep the load where the load case says it is.

Where the standard still rules

The load cases, the safety factors and the hold times are set by the standard and the customer's specification. The facility applies them exactly and records what happened.

It does not choose the numbers, and it does not certify the tower. That belongs to the operating laboratory.

The cycle

Erect, instrument, step, hold, then the next case.

A test runs from a stored load case, not from an operator's judgement, which is what makes one tower's result comparable with another's.

FIG · 02TRANSMISSION TOWER TESTING FACILITY · ERECT / INSTRUMENT / STEP / HOLD / NEXT CASE — PROPORTIONAL LOADING, AND THE ROPE-ANGLE PROBLEM

The step people underrate is the rope angle. As the tower leans, every rope changes direction, and the control has to steer the force back to where the load case wants it.

Fig · 03 — Three load cases on the same tower: wind across the line, a conductor pulled along it, and weight from above — a drawing of the idea, with no values.

1 · Erect

The prototype is bolted down on the test bed as it will stand in the field. The ropes are rigged to the cross-arm and peak attachment points.

2 · Instrument

Load cells go in at the tower end of every rope. Displacement, inclination and strain sensors go on the points the engineers chose.

3 · Step

The PLC raises every load point together, in the ratio of the load case, to the first step. The ropes take up slack before anything is counted.

4 · Hold

The loads are held while the movement settles and the tower is inspected. Nothing moves to the next step until the record and the inspectors agree.

5 · Next case

The tower is unloaded, the rigging is changed and the next load case runs from the stored plan.

6 · Prove or fail

The final case is taken to its specified value, and if the specification asks for it, on to failure. Either way the record shows where and why.

Work content

What the facility contains, element by element.

Read it as a checklist: a facility missing a row will buy that row later, at retrofit prices.

A bank of three servo winches on a galvanised steel skid in front of a concrete wall, each with a drum of steel wire rope, a gearbox and a motor, and a steel inline load cell in the rope, with the sensor cables running to a tidy rail on the wall

Fig · 04 — A bank of servo winches: a drum, a gearbox and a motor for each rope, and the load cell in the line — illustrative render.

Fig · 05 — The test bed from above: the tower at the centre, reaction structures and winch skids around it, and the control room outside the exclusion zone.

Element	What it does	What matters
Test bed	holds the tower down as it will stand	a rigid base, with anchor points for every leg
Reaction structure	takes the pull of the ropes	stiff enough that it does not move with the load
Servo winch	pays in and out rope under control	smooth at low speed, with a brake that holds on power loss
Rope and pulley train	carries the pull to the tower	rope angles set by the rigging plan
Inline load cell	measures the force at the tower end	what is recorded is what the tower felt
Displacement sensing	tracks how far the tower moves	tip, panel points and rope angle
Inclination sensing	tracks lean and twist	at the levels the engineers name
Strain gauges	read stress in chosen members	readings taken at every hold
PLC controller	drives every winch to its target	proportional loading, rope-angle tracking
Load-case library	stores each case as a plan	the same test can be run again
Data acquisition	records loads, movement and strain together	one time base for every channel
Protection	stops and lowers safely	overload, rope, drive and power-loss cases
Control room	operator and inspector work outside the danger zone	a clear view and a video record
Exclusion zone	keeps everyone clear of a failing tower	marked, interlocked and sized to the tower
Configurations	fixed station, winch set, control retrofit	one control and record system across all three
Training & handover	operators trained on the system	procedures and documentation

The row that decides whether a result can be trusted is never the size of the winches. It is the load cell at the tower end and the control that keeps the loads in ratio. A pull measured at the winch includes every loss in the rope, and none of it reached the tower.

Full specification — expand

System	Full-scale tower test facility: a rigid test bed with anchor points; reaction structures for the rope pull; servo-controlled winches with ropes, pulleys and inline load cells; displacement, inclination and strain measurement; a PLC that holds every load point to its target and tracks rope angle; a load-case library; a synchronised data record; protection and emergency lowering; and a control room outside the exclusion zone
The One Idea	The hard part is not the pull. It is pulling in proportion while the tower moves. Every load point must rise together in the ratio of the load case, while every rope changes angle as the tower leans
Why Test A Whole Tower	Calculation covers the members one by one. A full-scale test shows how joints, bolts, connections and members behave together, and finds the fault while it is still a drawing change
The Load Path	Winch, rope, pulley, load cell, tower. The load cell sits at the tower end of the rope, so friction and losses in the rope train are not counted as load on the tower
The Control Rule	Proportional loading: every load point climbs to its target at the same relative pace, and holds together. Rope-angle tracking: the measured position of the tower is used to keep each force in the direction the load case sets
The Load Cases	Wind across the line, a conductor load along the line, and vertical load, each stored as a plan of load points, ratios and holds, and combined as the specification requires
Measurement	Force at every rope; displacement at the tip and chosen panel points; inclination at chosen levels; strain in chosen members; all on one time base, with video, and readings logged at every hold
Safety	Operation from outside the exclusion zone; brakes that hold on loss of power; overload, rope and drive protection; an emergency release that lowers every load together; and respect for the energy stored in a stretched rope
Standards	IS 802 (Part 3, testing) and IEC 60652 (loading tests on overhead line structures) are public standards. The load cases, safety factors and hold times come from the standard and the customer's specification, and the facility applies them as written
Configurations	Fixed test station with test bed, reaction structures and control room; modular winch set for an existing test bed; and control and data retrofit for existing winches, with one control and record system across all three
Scope Boundary	The facility applies the loads and records the result. It does not design towers and does not certify them; certification and accreditation rest with the operating laboratory and its regulator. Loading of other structures is a separate design, as is fatigue testing on the servo-hydraulic fatigue machine
Status	Neometrix engineers transmission tower testing facilities to order, with servo-controlled winches that load a full-scale tower under PLC control, and no delivered transmission tower testing facility is claimed.

Configurations

One control and record system, three ways to build it.

The controller and the load-case library are shared. What changes is how much of the test station is new.

Fixed station

Complete tower test station

A test bed, reaction structures, servo winches, controls and a control room, built as one facility for a tower maker, a utility or a testing laboratory.

Winch set

Modular servo winch set

Skids of servo winches, with load cells and controls, for a test bed that already exists and needs more load points or better control.

Control retrofit

Control and data upgrade

A PLC, load cells and a data record for winches already in service, so the loads rise in step and every test is recorded the same way.

Fig · 06 — Three ways to build the facility, one control and record system: the same load cases run on a new station, on a winch set, or on upgraded winches.

And the part that is not steel at all, yet decides all three: the control software and the load-case library — plans written to your specification, and a record that a reviewer can follow line by line.

Where it is used

Wherever a lattice structure must be proven before it is built by the hundred.

The common thread is a structure whose failure is expensive, and which is cheaper to break once on the ground.

Tower manufacturers

A new design is proven on a prototype before the first order is fabricated, and the record goes to the buyer with it.

Utilities and grid companies

Type tests on the towers a line will use, run to the load cases the utility specifies.

Testing laboratories

A station that runs different designs for different clients, with every load case stored and every test recorded the same way.

Telecom, railway and substation structures

Masts, gantries and support structures that share the same need: known loads, in a known ratio, on a whole structure.

FAQ

Common questions.

Longer answers, for readers who want the reasoning.

Q · 01 Why test a whole tower when every member is calculated?

Because a tower is not a set of separate members. It is hundreds of members joined by bolts, plates and connections, and the way they share load depends on details that a calculation has to simplify: how a bolted joint slips before it grips, how a member framing in at an angle loads its neighbours, how a leg extension or a stub behaves under the combined pull. A calculation is very good at each member and honest about none of those interactions. The full-scale test is where they show up. Bolts slip, a member bows earlier than expected, a joint that looked generous turns out to be the weak one. The value of finding that on a test bed is plain. On the ground the fix is a change to a drawing and a re-test. On a built line it is a repair campaign across every tower of that design. That is why a new design is normally proven on a prototype before the first order is fabricated, and why the test is run to a written specification, load case by load case, rather than to the judgement of whoever is at the winch.

Q · 02 Why servo-controlled winches, not hand-operated winches or a jack?

Because the test is not one pull. It is several pulls that must rise together, and a hand-operated winch cannot keep several loads in ratio while the tower moves. Each operator loads at a different pace, the loads drift apart, and the tower is briefly loaded in a pattern that no real wind or broken wire would produce. A servo-controlled winch does three things a hand winch cannot. It holds a commanded force smoothly, including at very low speed, where a rough drive would jerk the rope. It pays in and out at the pace the tower actually moves, so the force stays where it was set. And it answers to a PLC that knows what the other winches are doing, so every load point climbs to its target at the same relative pace and holds together. A hydraulic jack has the force but not the stroke for a large tower's movement, and ropes and winches suit the long travel a tower needs. The servo drive also makes the test repeatable: the same load case run on the second prototype is the same load case, applied the same way.

Q · 03 What happens to the loads when the tower leans?

They change direction, and this is the reason the control is more than a force loop. A rope can only pull along its own line. When the tower is straight, the rope leaves the cross-arm at the angle the rigging plan sets, and the pull has the transverse, longitudinal and vertical parts the load case wants. When the tower leans under load, the cross-arm moves, the rope angle changes, and those parts change with it, even if the force in the rope is exactly as commanded. The result is a test that is quietly wrong. The facility therefore controls force and geometry together. The displacement sensors report where the attachment points are, the controller works out the direction each rope now pulls in, and it adjusts the rope forces so that the parts the load case calls for stay where they should. The rigging is also planned so that rope angles stay within a range the control can manage over the tower's expected movement, and the travel limits of every winch are set from that plan, not left to chance.

Q · 04 What happens if the tower fails during the test?

The facility is designed on the assumption that it might, because a test taken to failure is one of the things it is for. Three design rules follow. First, nobody is in the danger zone: the operator and the inspectors work from a control room outside an exclusion zone that is sized to the tower, and the loading cannot start unless the zone is clear. Second, the energy stored in the ropes is respected. A stretched rope releases its energy quickly when the load on it vanishes, so the rigging is planned to keep rope, pulley and anchor loads within their ratings, and the winch brakes hold on loss of power rather than releasing. Third, an emergency release lowers all the load points together, not one at a time, so that a failing tower is not pulled sideways by the ropes that remain. After a failure the value of the test is in the record: the loads, the movement and the video, on one time base, show which member or joint gave way first, and that is the answer the designer wants.

Q · 05 What is measured, and where?

Four kinds of thing, all on one time base. Force: a load cell at the tower end of every rope, which is the number that matters, because a pull read at the winch includes every loss in the rope train and none of that reached the tower. Movement: displacement at the tower tip and at chosen panel points, which also gives the rope angles the control needs. Lean and twist: inclination at the levels the engineers name. Stress: strain gauges on the members the design team wants watched, read at every hold. Around those sit the things that are not numbers, such as video of the tower and a note of where bolts have slipped or members have bowed, recorded against the load at which they were seen. The data acquisition keeps every channel in step, so a reviewer can line up a strain reading against the exact load that caused it. Which points are instrumented is the design team's call; the facility provides enough channels, and a tidy way to add more, so that call is not limited by the equipment.

Q · 06 Has Neometrix built one of these?

We would rather answer this plainly than let a page imply otherwise. Neometrix engineers transmission tower testing facilities to order, with servo-controlled winches that load a full-scale tower under PLC control, and no delivered transmission tower testing facility is claimed. What stands behind the offer is adjacent and real. Neometrix engineers load-and-measure test rigs that apply a controlled force and record what the article does: our servo-hydraulic fatigue testing machine and our impulse and load test rig are two of them. We build PLC control and data acquisition into those rigs, and we fabricate the heavy steel that reaction structures and test beds are made of. So the honest position is this: the class is engineered to order, the engineering disciplines are in the building, and the first tower test facility of this exact type will be built around a customer's towers and site rather than lifted off a shelf. If that matters to how you buy, say so early and we will scope it that way, with the reference work open to inspection.

Q · 07 Which standards does a tower test follow?

Two public standards are the usual starting points. IS 802 (Part 3) covers the testing of overhead transmission line towers in India, and IEC 60652 covers loading tests on overhead line structures internationally. Neither is a description of a machine. They set out what a test must show: the load cases to be applied, how the loads are raised and held, and what is to be observed and reported. The actual numbers for a given tower, the design loads, the safety factors and the hold times, come from the standard as applied by the customer's specification, and they differ from one utility and one tower type to the next. That is why this page quotes none of them. The facility is built so that whatever the specification says can be entered as a load case and applied exactly, and so that the record shows it was. Two points are worth stating clearly. First, Neometrix does not design towers and does not certify them. Second, accreditation of a test station, and the acceptance of its results, rest with the operating laboratory, its accreditation body and the buyer, not with the equipment supplier.

Q · 08 What do you need from us to quote?

Six things, and most of them are about your towers rather than about our winches. First, the towers: the largest you will test, in height, base width and mass, and how varied the designs are. Second, the loads: the largest force at any one load point, the number of load points at once, and the load cases in your specification. Third, the measurements: which movements and strains your engineers want recorded, and in what report format. Fourth, the site: the ground and space you have, whether a test bed or reaction structure already exists, and whether it is to be reused. Fifth, the level of automation: fully automatic load cases, or operator-stepped with the control keeping the loads in ratio. Sixth, the setting: a new station, an added winch set for an existing bed, or a control retrofit for winches in service. From that we come back with a system definition you can check, a plan of the test bed, a control and measurement specification and a budgetary price. If you would rather start with a conversation, that works too — most of these projects begin with somebody describing a tower they would like to have broken on the ground.

The rigs beside it, that apply a load and record the result.

Three neighbours in the same load-and-measure test family.

↗ The servo control side

Servo-Hydraulic Fatigue Testing Machine

The same closed-loop idea at bench scale: a commanded force, a measured force, and a record of what the article did.

↗ The load rig family

Impulse & Load Test Rig

A rig that applies defined loads to an article and records the response, built to a written test plan.

↗ The heavy load rigs

Helicopter Main Gearbox Load Test Rig

Heavy loads applied under control to a large article, with the loads and the response recorded together.

Browse all Neometrix product lines.

Get a quotation

Tell us the tower, the loads,
and the measurements you need.

The projects desk replies within two working days with a system definition you can check, a plan of the test bed, a control and measurement specification, and a budgetary quotation. Write to [email protected] or use the form.

Enquire — tower test facility Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED-TO-ORDER CLASS — TRANSMISSION TOWER TESTING FACILITY ERECT · INSTRUMENT · STEP · HOLD · NEXT CASE — PULL IN PROPORTION ENGINEERED IN NOIDA · INDIA

Prove the tower on the ground, not on the line.

Why a whole tower is pulled, and not only calculated.

What the facility is actually for

Why the loads must rise together

Why the ropes are the hard part

Where the standard still rules

Erect, instrument, step, hold, then the next case.

1 · Erect

2 · Instrument

3 · Step

4 · Hold

5 · Next case

6 · Prove or fail

What the facility contains, element by element.

One control and record system, three ways to build it.

Complete tower test station

Modular servo winch set

Control and data upgrade

Wherever a lattice structure must be proven before it is built by the hundred.

Tower manufacturers

Utilities and grid companies

Testing laboratories

Telecom, railway and substation structures

Common questions.

The rigs beside it, that apply a load and record the result.

Servo-Hydraulic Fatigue Testing Machine

Impulse & Load Test Rig

Helicopter Main Gearbox Load Test Rig

Tell us the tower, the loads,
and the measurements you need.

Similar Products

Share This Page

Prove the tower on the ground, not on the line.

Why a whole tower is pulled, and not only calculated.

What the facility is actually for

Why the loads must rise together

Why the ropes are the hard part

Where the standard still rules

Erect, instrument, step, hold, then the next case.

1 · Erect

2 · Instrument

3 · Step

4 · Hold

5 · Next case

6 · Prove or fail

What the facility contains, element by element.

One control and record system, three ways to build it.

Complete tower test station

Modular servo winch set

Control and data upgrade

Wherever a lattice structure must be proven before it is built by the hundred.

Tower manufacturers

Utilities and grid companies

Testing laboratories

Telecom, railway and substation structures

Common questions.

The rigs beside it, that apply a load and record the result.

Servo-Hydraulic Fatigue Testing Machine

Impulse & Load Test Rig

Helicopter Main Gearbox Load Test Rig

Tell us the tower, the loads,and the measurements you need.

Similar Products

Share This Page

Tell us the tower, the loads,
and the measurements you need.