Harrington TF2/TS2 Chain Hoist Trolley Flange Clearance by Measuring A
On a Harrington TF2/TS2 trolley, beam flange clearance is not a number you look up; it is a range you measure against your own beam. The manual defines the fit as dimension A, the spread across the fully extended side plates, compared with dimension B, the beam flange. You measure A, compare it with B, and move spacers until the difference sits inside the band for the unit's capacity.
That holds for this series only. If the trolley on your floor is another make or model, or its own manual states an absolute clearance instead of a difference against B, this method does not transfer; read that unit's documentation before you touch a spacer.
Clearance Is a Measured Gap, Not a Setting
The trolley wheels carry the load on the beam flange, and the side plates hang outside the flange edges. What decides whether the trolley tracks straight or drags is the margin between the plate faces and the flange edge. Because flange thickness changes from beam to beam, that margin cannot be written as one fixed gap; it can only be written relative to the flange you actually have overhead. That is why the procedure asks for A measured and compared against B rather than for a single clearance number.
A trolley set too tight has no room to run without the plates rubbing the flange; one set too loose can skew and walk instead of tracking. Both outcomes come from the same error: treating clearance as a setting you dial in from a chart rather than a fit you confirm on the beam in front of you.
Suppose a maintenance tech measures A on a beam with a thick flange and finds the gap tight. The instinct is to hunt for the number that says how big the gap should be. There is no such number here: the flange is the reference, and the only useful question is how much larger A is than this particular B.
Step One Is Spreading the Side Plates Fully
The manual's order is short. With the hoist off the trolley, make sure both side plates are spread fully outward, measure dimension A across them, then compare that reading with the value for your capacity band. Spreading first is not a formality: a partly spread plate gives an A smaller than the real one, which means a bad number can pass as good and send you chasing a spacer problem that does not exist.
Take the reading at the plates themselves, with them at full outward position, not at the spacers or along the shaft. Everything downstream inherits whatever error you make in that one measurement, and no later step catches it. Picture a two-person job: one person holds the plates at full spread while the other runs the tape or caliper. It sounds fussy for a measurement that takes seconds, but a plate that eases back between setting and reading hands you a number that is wrong in the direction that matters.
Two Capacity Bands, Two Clearance Ranges
On this series the requirement splits by capacity. For trolleys up through 5 Ton, A must be 3/32" to 5/32" greater than B. For trolleys 8 Ton to 20 Ton, A must be 3/16" to 1/4" greater than B. Both figures belong to the Harrington TF2/TS2 adjustment procedure and to nothing else, so read the capacity off the unit rather than inferring it from the beam or from the hoist hanging under it.
The heavier band is the one stated for 8 to 20 Ton. Geometry and load explain the direction: a heavier trolley carries more load through larger parts, so it is given more running room before the plates bind. That is an explanation, not permission to split the difference between the two bands or apply the tighter figure to a heavier unit.
Spacers Move the Plates; the Gauge Confirms It
The spacer stack is the adjustment.
Nothing else on the trolley sets how far apart the side plates sit. If A falls outside the range, move spacers from inner to outer or outer to inner until A lands in the band. The reason the spacers are the adjustment is that they are the physical stack between the plates: shift them outward and the plates move apart, shift them inward and they come together, and the caliper tells you which way to go on the next pass. What you are chasing is the reading after the move, not the arrangement someone used on a different beam. Because two traversing units are combined in the 15 and 20 Ton trolley, always adjust both units in the same way. Mismatched halves defeat the point of a range that is meant to hold across the whole trolley.
If A comes up short, the plates need to go further apart, so the spacer you move travels from the inside stack to the outside one; if A comes up long, the move runs the other direction. Each pass ends at the caliper, not at the diagram.
Lock the Shaft Stopper Pin Into Hole A
With A inside the band, the hardware goes in. For trolleys 8 Ton to 20 Ton, make sure to insert the Shaft Stopper Pin into Hole "A"; Hole "B" is for trolley installation only. After the adjustment is correct, install the Shaft Stopper Pin, insert the Split Pin into the Stopper Shaft Pin, and securely bend both branches of the Split Pin.
The manual treats the two holes as different: Hole B is for trolley installation only, so the stopper pin location is not interchangeable. This arrangement is documented for this series only; on any other trolley, take the pin location from that unit's own manual instead of carrying this step across.
Why the Manual Says Ignore the Table
The instruction to move spacers irrespective of the numbers in Table 3-2 is doing real work. It makes the table a starting reference rather than a target, which means the table cannot be the thing you sign off against. What you sign off against is the measured A compared with B.
If a copied or extracted table has ambiguous columns or merged cells, treat its digits as unusable and work from the measurement instead. A beam with unusual or worn flanges is a question for the trolley manufacturer for that model, not something to settle by nudging the number a little and hoping.
If you are buying the trolley rather than installing it, the same comparison decides whether it will fit at all: ask what flange range the side plates cover at full spread, and how that range sits against your beam flange plus the band your capacity requires.
The Measurement That Ends the Adjustment
The adjustment is finished when both plates are fully spread, A is measured again, and A minus B sits inside the band for the unit's own capacity. On a 15 or 20 Ton trolley that confirmation extends to the second traversing unit, which has to show the same adjustment as the first, and to the Shaft Stopper Pin sitting in Hole "A" with the Split Pin fitted and both branches bent.
A reading that is close but outside the band is not a pass. Re-checking after a spacer move costs a few minutes; re-checking once the trolley is under load with a hoist hanging from it costs a lift, a shutdown, and an argument about who signed off.
Before any spacer moves, confirm one baseline: the actual flange thickness B on the beam the trolley will run on. Every requirement here is written as A being a set amount greater than B, so a wrong B points every later step at the wrong target. The capacity band tells you how much greater; the beam tells you what greater means. That is the check to make first.