During construction of the light rail two straights are to be connected by a circular curve, as shown in the diagram below. In order to avoid damage to a drainage pit the centreline of the road MUST be exactly 1.7 metres from the pit at the mid-point of the curve. The bearings of the straights of the road, and the bearing and distance from the intersection of the straights to the pit are shown on the sketch below. a) Calculate the exact length (to three decimal places of a metre) to meet this condition. (8 marks) IT WAS THEN DECIDED TO USE A CURVE OF EXACTLY 250 RADIUS. FOR ALL FOLLOWING CALCULATIONS USE R=250. b) In the table below, show the bearings and distances from the first tangent point to set out points A and B which are 100 metres and 200 metres respectively from the first tangent point. (6 marks) c) If the chainage of the intersection point is 1200, calculate the chainages points. (6 marks) the first and second tangent IP 5821'00" TPI. NOT TO SCALE Libraty Cop Answers: a) Exact length of curve: b) Information to set out A and B from TP1 POINT BEARING A DISTANCE B c) Chainage of TP1 Chainage of TP2