Arrows (Chain pins):

• Accompanying each chain are 10 arrows.
• They are also called marking or chaining pins, and are used to mark the end of each chain during the process of chaining. They are made of good quality metallic wires of 4 mm in diameter and of a minimum tensile strength of 700N/ mm2. The wire is black enameled.
• The arrows are made 400 mm in length, are pointed at one end for inserting into the ground and bent into a ring at the other end for facility of carrying.
• They should have a piece of white or red tape tied to the ring so that they can be made easily visible at a distance.
• To mark the end of each chain length, the arrow is inserted in the ground, but when the ground is hard, a scratch may be made with the pointed end.

Plumb bob

• A plumb bob consists of a metal weight made of brass with a pointed end.
• It is suspended by a string and is used to locate points directly below or above another point.
• It is also used for accurately centering of compass or level or theodolite over a station mark, and for testing the verticality of ranging poles.

Pegs

• Wooden pegs are used to mark the positions of stations.
• They are made of hard timber and are tapered at one end.
• They are usually, 2.5 cm square and 15 cm long, but in soft ground, pegs 40 to 60 cm long and 4 to 5 cm square suitable.

Off-set rod

• The off-set rod is similar to the ranging rod but is usually 3 m long and is divided into parts each 0.2 m in length.
• It is chiefly used for aligning the off-set line and measuring short off-sets.

Cross-Staff

Cross-staff is used for

(i) Finding the foot of the perpendicular from a given point to a line, and

(ii) Setting out a right angle at a given point on a line. There are three types of cross-staff, namely, (1) the Open (2) the French (3) Adjustable, the first one being in common use.