Double Decker Rail Coach Conceptual Seating Plan

Abstract

AC Chair Cars in trains on IR network usually have a seating plan in 2+2 or 2+3 format in Executive Class and Economy Class respectively. Middle seat in the row with 3 seats is a constraint and many passengers do not opt for it. The limitation in the row with 2 seats is that the passenger in the window seat while moving in or out necessarily have to cross the passenger in the aisle seat or the aisle seat passenger is required to give way by moving out. The later issue to certain extent is eased by providing larger seat pitch as in coaches with Executive Classes. However, this is still a limitation. This article examined the conceptual seating plans in 1+1+1 and 1+2+1 format to eliminate the limitations and its impact on the capacity.

ClickHere for PDF Version – DD Rail Coach Conceptual Seating Plan

Introduction

Mass Transport Operators (MTOs) of BAR (Bus / Airplane / Rail) modes often need to balance between LOS (Level of Service) and capacity. MTOs adopt a seating plan of either of the two formats m+n (2-R – 2 Rows) or m+l+n (3-R 3 Rows) with “m” and “n” usually having values of 2 or 3 and rarely 1. The later format is currently adopted in wide body airplanes with “l” usually taking a value between 2 and 5 and rarely 1 when “m” and “n” are also valued at 1. The seating plan and choice of values for the three variables varies between different MTOs even on the same sized rolling stock depending on the traffic demand they are targeting to cater to and the LOS they would like to offer to the passengers.

Indian Railways (IR) on some of its short and medium distance routes operate trains with seating accommodation (Chair Cars – CCs) in 2-R format during the day time services.  The capacity of CCs by class of service and train categories varies between 56 and 120 as described in the post entitled “Double Decker Sleeper Coach”.

LOS

LOS varies across the coaches in accordance with the aisle width, seating plan format and the seat sizes [width and pitch (leg room)] adopted to achieve the desired capacity. In general trains with CCs are being operated by Single Deck (SD) AC / non-AC coaches. The seating plan of SD Economy (EC) and Executive (EX) classes in AC coaches is 2+3 and 2+2 respectively. The seat pitch of SD-EX is about 150 mm more than that of SD-EC and seat width over 100 mm. Double Decker AC Chair Cars (DD-AC-CCs) has been introduced in to service in the past few years. The capacity in DD-EC and DD-EX with seating plan being similar to that in SD coaches is over 50 and 20 percent of the capacity in corresponding SD coaches. This, for example, in DD-EC has been achieved by reducing the LOS or seat size marginally in comparison to that of SD-EC. The reduced seat size is however, still comparable to some Economy Class seats in some airlines.

Constraints

The seating plans of 2+3 and 2+2 have certain limitations or constraints. The major constraint in the row with 3 seats is the middle one. The passengers in the middle seat feel sandwiched between the passengers on either side. This seat is generally not preferred by passengers and the operators also allot these seats when occupancy is reaching its capacity and the seats towards window or aisle are not available. The limitation in the row with 2 seats is that the access to the widow seat is across the aisle seat. That is the passenger in the window seat while moving in or out necessarily have to cross the passenger in the aisle seat or the aisle seat passenger is required to give way by moving out. This is true of middle seat passenger as well. In fact this limitation multiplies in rows with 3 seats (or more as in some airlines). The later issue to certain extent is eased by providing larger seat pitch as in coaches with Executive Classes. However, this is still a limitation.

LOS and Capacity Enhancement

The limitations suggested the need to explore alternate seating plans to reduce / eliminate the stated constraints and limitations and examine the impact on capacity. This resulted in the preparation of two conceptual layouts (ALT-1 & ALT-2) as shown.

The ALT-1 considered the placement of seats in 3R (1+1+1) format in lower and upper decks (LD / UD) and in 2R (1+1) format in middle deck (MD). The seat width suggested for middle row is 560 mm and that on the sides could be same or wider up to a maximum of 610 mm in accordance with the design constraints (50 and 5 mm in LD & UD respectively) due to sidewalls of the coach. The suggested seat width is halfway that of the width of seats in SD-EC and SD-EX coaches. The suggested seat pitch is 870 mm similar to that in DD-EC which is reasonable. The suggested seat pitch is assumed sufficient for the suggested seat plan [1+ (0/1) +1] eliminates the need for a passenger to move across an aisle seat passenger to access the seat(s) adjoining the aisle seat. This arrangement results in the provision of 31 seats in LD and equal number in UD. The MD on the side with services (Electrical/Pantry) can accommodate 4 seats and 8 on the other side giving a total capacity of 74 seats in the coach. The capacity in ALT-1 is 30+ percent more than that in SD-EX and about 9 percent more than that in DD-EX.

The ALT-2 considered the placement of seats in 3R (1+2+1) format in LD & UD and in 2R (1+1) format in MD. The seat width suggested for middle row is 453 mm and that on the sides could be same or wider up to a maximum of 503 mm in accordance with the design constraints, as in ALT-1, due to sidewalls of the coach. The seat pitch and aisle width is similar to that in DD-EC coach. This seat size is comparable to the size of economy class seats in some airlines. The seats in MD are suggested to be wider at 560 mm with seat pitch being same as that in LD and UD. The suggested seat sizes and arrangement results in provision of 40 seats each in LD and UD giving a total capacity of 92 seats in the coach. The capacity of ALT-2 is 35+ percent more than that of DD-EX coach. This arrangement also eliminates the limitation of a passenger moving across the aisle seat passenger to access the seat(s) adjoining the aisle seat. Additionally it eliminates the constraints experienced by a middle seat passenger.  The capacity is however 20+ percent lower than that in DD-EC coach.

A coach with layout as suggested in ALT-2 can be positioned as Business or Premium Economy Class between Executive and Economy Class coaches. This can perhaps attract some passengers who are lost to trains due to inconvenience of travelling in an economy class or high fare of executive class travel.