The roller and plate act as a low-friction bearing surface. As the piston extends and the rocker arm (connected to the rigging) moves, it can impart a slight rotational or angular force, and the rollers allow this movement smoothly.

Step (v) in section 608f is: "Remove front cover, release spring, piston trunk subassembly with trunion body and ratchet with adjusting screw."

Section 603b(ii) mentions "particularly high temperature occur... (maximum 400°C on the opposing friction surface)."

Section 608h's preamble instructs to apply grease to all moving parts. Specifically greasing the cylinder body and piston packing ensures the packing slides smoothly and maintains a good air-tight seal against the wall.

In engineering, when a cylinder is referred to by a size like 8" or 203mm, it almost always refers to the bore diameter (the internal diameter of the cylinder, which is the size of the piston). 203mm is the metric equivalent of 8 inches.

Precaution (vii) states that ignoring the red mark will result in an "increased gap between wheel and brake blocks." The adjuster can't take up any more slack, so the gap grows with further wear, reducing braking force.

Section 603a lists "Reduction in the replacement of brake blocks vis a vis cast iron due to higher wear life" as a key benefit of composite blocks, which is quantified by the lower wear rate in Table 6.1.

Test No.1 in section 608i specifies repeating the test at 3.8 kg/cm² "with cock 3 closed limiting the maximum piston stroke to 95mm."

Table 6.2 describes Item 21 as "Jubilee clip" for the dust excluder, and the assembly steps in 608h(xv) and (xvi) mention clamping the dust excluder with jubilee clips.

Special precaution (vi) directly links maintaining the 5mm gap to ensuring the initial piston stroke (before slack adjuster action) stays within 32 mm.

Section 603b(iv) states: "The material must not attack the opposing friction surface or give rise to the formation of metal inclusions."

The pawl is a key part of a ratchet mechanism. Its function is to allow rotation in one direction (during release) while preventing it in the other (during application), which is how the slack adjuster "inches" out.

As the wheel wears down, the bogie sits lower. Packing at the axle box lifts it back up. Precaution (v) links this packing to the need to re-adjust the pull rod, showing how these two actions are related to maintaining correct geometry.

Section 601(d) already gives different mechanical advantages for Non-AC and AC coaches. Using the wrong parts would alter this carefully designed geometry and force ratio, leading to inefficient or unsafe braking.

The procedure in 608i (Test 2C & 2D) involves simulating a condition that requires resetting and then performing the reset, while checking that the dust excluder collar is free and does not twist.

Section 608f(iv) and the note for item 15 in the dismantling procedure both mention the release spring is compressed with a force of 60 kg.

Precaution (v) links the shifting of the pull rod specifically to the wheel diameter reducing to 839mm and the provision of 38mm packing at the axle box.

Section 603e states the material code includes 'KA' for asbestos type.

Section 608j(i) provides this specific detail: "2 Nos. of spring washers are kept inside in between them (one each side) in first two bolts, so that the rollers can move smoothly in the cover plate in angular position."

Section 608h(xii) states to tighten the front cover bolts "with a tightening torque of 200 kg·cm."

The table in 603f clearly maps 'K' type CBB to "All coaches with bogie mounted brake system."

Section 608i, in the "Preparation for Test" section, notes: "During testing cock 2 must be opened slowly whenever the cock is used to admit air under pressure to the cylinder."

Section 608g advises, "Check all the springs for possible corrosion and distortion. It is advisable to change the springs on every POH." This is a proactive safety and reliability measure.

Section 608d states: "by turning the adjusting tube sub-assembly in clock wise direction the distance between piston to cross head is reduced to minimum level."

Section 608c explains that hand brake trunnions are fitted for the hand brake and "During the service application the hand brake trunion does not move."

Section 606 states: "to maintain the system, instructions contained in the Air Brake System (chapter 4) will have to be followed in addition to those... for brake cylinders."

In a lever-based system like brake rigging, mechanical advantage is the ratio of output force (at the brake block) to input force (from the cylinder piston). A higher number means more clamping force.

A higher coefficient of friction means more braking force is generated for a given force pressing the block against the wheel, directly contributing to the reduced braking distance (800m vs 905m) noted in Table 6.1.

Section 601(f) states that a "15mm bore pneumatic pipeline has been laid over bogie frame to inter connect the brake cylinders of one bogie."

Section 601(b) states the adjuster is for "taking the slack created between wheel and brake block on account of wheel / brake block wear." The 305mm capacity is the total slack that can be taken up.

Special precaution (ix) in section 607 states: "The rocker from position of Brake Cylinder should be kept in horizontal axis of cylinder before fitment."

Section 608j(iii) provides this specific instruction: "the notch portion of the tooth of pawl housing ring should be filed till it matches with the teeth of Ratchet screw."

Note 1 under Test No.2 in section 608i states that the piston should be operated at full stroke at least 18 times "to test all ratchet teeth."

Section 608i, Test No.2B, instructs to let the piston move out slowly until the operating pawl is heard to "click over" and then measure the take-up stroke, which must be 32 mm.

Test No.1 in section 608i first charges the cylinder to 0.7 kg/cm² and checks for leaks. It then repeats the test with the cylinder charged to 3.8 kg/cm².

Section 608f(vii) explicitly states that the piston and piston trunk sub-assembly are a matched pair and are not interchangeable, advising to put an identification mark on them.

The sequence in section 608f shows that after step (iii), the next step (iv) is to unscrew the hex nuts M12 slowly, with a warning about the 60kg force of the release spring.

Special precaution (vii) explains that the rigging is designed so the red mark (indicating full extension) will not appear until the wheel is at 839mm and the block is fully worn, meaning block replacement and resetting happen together.

Special precaution (v) in section 607 clearly states that when the wheel diameter reaches 839mm, the pull rod connection must be shifted to the adjacent hole.

Special precaution (iv) in section 607 emphasizes that they must be fitted as shown in the drawings and not reversed, as the curved profile is engineered to work in a specific orientation within the linkage.

Table 6.1 directly provides these comparison values, showing the bogie-mounted system has fewer wearing parts and lower block wear.

Section 604c explains that when the piston stroke exceeds a pre-determined value, a ratchet mechanism turns "during return stroke, the adjusting movement takes place."

Section 604a states that the reduction in brake pipe pressure "is sensed by distributor valve to operate brake cylinder." It does this by connecting the auxiliary reservoir to the brake cylinder.

Section 604a explains that after the first block contacts the wheel, the lever pivots and moves forward, pulling the pull rod (7) which then swings the second lever (8) to apply the second block.

Section 603b(iii) states that the blocks must be able to wear down to a thickness of 12 mm, including the back plate, without the backplate contacting the wheel.

Section 603b(ii) specifies that under the effect of dampness or high temperatures, the coefficient must not vary by more than ±15% relative to the value obtained during braking in a cold and dry state.

Section 601(e) and special precaution (v) in 607 both describe the pull rods as having a single hole at one end and two holes at the other end for slack adjustment.

Section 601(b) mentions the take-up stroke of 32 mm. Test No.2 in section 608i mentions limiting the maximum piston stroke to 95mm for the leakage test, indicating this is the full design stroke.

Section 601(b) specifies that four cylinders of 8" size are provided per coach in place of two cylinders of 14" in the standard system.

Section 601 states the system was introduced "to overcome the problems of slack adjuster failure as well as problems associated with cast iron brake blocks."