BYD BC12A04

The BYD B12 is an electric single-deck city bus offered by Chinese bus manufacturer BYD Auto Industry (比亞迪). As of 2023, it is BYD’s flagship electric city bus, superseding the highly successful BYD K9.

BYD is supplying 300 units of BYD B12 buses (registered as BYD BC12A04 for this sub-type) to the Land Transport Authority (LTA) under Contract PT601A. This comprised an initial tender award for 240 units in November 2023, and an LTA-exercised option for 60 more units announced in October 2024.

• Private Bus Operator-owned BYD B12 buses
• LTA trial BYD B12 bus (SG4013A)

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Bus Model background

BYD launched its ‘B-series’ electric bus range on 29 July 2020, comprising the single-deck BYD B10 and BYD B12 of 10 and 12-metre lengths, and the BYD B12D 12-metre double-deck bus.

The BYD B12 is powered by twin wheel-hub hairpin motors that are directly connected to the driven wheels, maximizing available cabin space by eliminating the need for a transmission and driveshaft. A ‘6-in-1 electronic controller’ with SiC elements simplifies the vehicle’s electronics, by combining 2 electric motor controls, a steering control unit, an air compressor controller, a DC-DC converter and a power distributor unit into a single module.

BYD also offers the bus with Blade batteries, a proprietary lithium iron phosphate (LFP) battery design optimised for energy density and safety. These batteries are water-cooled to maintain their optimal working range, and paired with a battery management system for performance monitoring. These batteries can also be integrated into the chassis, but this was not opted for in LTA’s BYD BC12A04 order.

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LTA Procurement (2023)

On 25 November 2023, the LTA awarded BYD (Singapore) Pte. Ltd. was awarded a contract by the Land Transport Authority (LTA) to supply 240 single-deck electric buses for S$108.1 million as part of Contract PT601. This contract also included 120 Zhongtong N12 buses supplied by Cycle & Carriage (in partnership with Zhongtong Bus). BYD later confirmed via a Facebook post that the buses would be BYD B12 models.

On 23 October 2024, LTA announced that it had exercised an option to purchase 60 additional BYD buses, increasing the total to 300 buses. Electric bus chargers were also installed at Sengkang West, East Coast and Gali Batu Bus Depots under Contract BD401 to support these buses.

 

Buses were first sighted in Singapore sometime in late August 2024. The buses, identified in delivery documents by the model name GTK6127BEVB1, were later registered under the model name BYD BC12A04. Some units were delivered without seats and handrails, which were installed locally.

The “C” in the model name likely signifies “chassis,” reflecting BYD’s supply of chassis-only units with bodywork by Zhuhai Guangtong.

Registration

The registration numbers SG3101K–SG3400Y were reserved for the BYD BC12A04 buses. Registration commenced on 14 October 2024, with the first 10 units (SG3102H–SG3111G) leased to SBS Transit.

In a press release on 23 October 2024, LTA mentioned that the first 10 electric buses procured under PT601 would commence passenger service from December 2024, on Bus Services 86, 107 & 159, utilizing the charging infrastructure at Sengkang West Bus Depot.

In November 2024, before entering revenue service, SBS Transit provided several BYD BC12A04 buses for the LTA-UITP Singapore International Transport Congress & Exhibition (SITCE) as shuttle services for event delegates and visitors. Thirteen buses (SG3102H–SG3111G, SG3113B, SG3117R & SG3118M) were wrapped in a two-thirds advertising wrap promoting SBS Transit’s corporate achievements.

Revenue Service

Revenue service commenced on 2 December 2024, with buses deployed on Bus Services 86, 107 & 159. As Sengkang West Bus Depot had yet to be commissioned, an interim arrangement saw these buses charge during the mid-day period at Seletar Bus Depot. The 150 kW CCS2 chargers at Seletar Bus Depot were installed for overnight charging of BYD K9 buses, and are thus available for use by BYD BC12A04 buses in the daytime.

The first few days of revenue service also saw some buses prematurely withdrawn from service due to malfunctioning camera mirrors.

Buses are also operationally restricted from entering tunnels (eg. CTE/KPE/MCE) and basements (eg. Changi Airport), with a red sticker pasted on the steering wheel to remind drivers.

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Preliminary Specifications

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Model Overview & Exterior

The BYD BC12A04 buses are built by Zhuhai Guangtong Vehicle Manufacture Co., Ltd., a contract manufacturer of buses based in Zhuhai, China. BYD supplies the bus chassis, while Zhuhai Guangtong assembles the completed bus in Zhuhai before delivery to Singapore.

Unlike the earlier BYD B12A03 trial bus (SG4013A), which featured a distinctive “bulbous roof” integral bodywork designed by BYD, the BC12A04, referred to as GTK6127BEVB1 by Zhuhai Guangtong, represents a refreshed bodywork design launched by Guangtong for the GTK6127BEVB line of electric buses sometime around 2023.

The bus incorporates aesthetic elements such as triple-grouped headlights and taillights, black accent bands between headlights and along the roof, and roof skirts that visually minimize the battery pack and air-conditioning unit for a sleek and modern appearance. The headlight/taillight design is similar to those used on Alexander Dennis buses—which Zhuhai Guangtong also manufactures under contract.

The full-low-floor design with three passenger doors is enabled by the bus’ compact electric drivetrain, with the rear drive axle powered by two 150 kW direct-drive in-axle motors. BYD Blade traction batteries are distributed around the floor, rear, and roof of the bus. Chassis-integrated batteries were not opted for in these buses.

Buses procured under Contract PT601 (i.e. BYD BC12A04 and Zhongtong N12) also use camera mirror systems, hence the absence of the usual wing mirrors.

Interior

The BYD BC12A04 features a fully low-floor design for step-free access throughout the bus. It includes three doors: a front entrance, a middle exit, and a rear exit door. This layout facilitates ease of passenger boarding and alighting.

Seats are the Ster 8MI model, upholstered in blue for general use (12 seats) and maroon for priority seating (16 seats). The rear double-leaf door allows convenient alighting, while a small floor step provides access to the last row of seats. However, this design prioritizes accessibility over capacity, accommodating only 28 seated passengers, with 8 seats rear-facing to accommodate wheel wells.

The rear section of the bus features 8 pairs of seats, in a seating layout similar to other Chinese 3-door electric buses supplied to LTA, including the Zhongtong N12 production batch. A floor step is provided for passengers accessing the last row of seats, despite being positioned at the same height as the facing seats in front.

Accessibility

LTA specifications call for two wheelchair bays for passengers travelling in wheelchairs (PIWs) or using personal mobility aids. Both wheelchair bays are located opposite the exit doors.

Each bay has a foldable rear-facing seat integrated into the backrest, which does not count towards the seating capacity. Pivoting handlebars can be deployed or stowed for convenience; this particular design locked via an index plunger first appeared on ADL E500 3-door buses.

Contract PT601 buses (i.e. BYD BC12A04 and Zhongtong N12) come fitted with automated boarding ramps which can be deployed at the push of a button located on the exterior of the bus near the middle door. This feature is expected to reduce strain on bus drivers, who have to lift the manually operated ramps and then fold them back on older buses. According to the LTA, these ramps are equipped with sensors which detect obstacles and align with the kerb for smoother deployment.

A stroller restraint is also included with the front wheelchair bay. Since 2017, open strollers have been allowed on public buses.

Other Passenger Features

The BYD BC12A04 buses are installed with Electronic Display Sign (EDS) and Passenger Information Display System (PIDS) units from Luminator.

The interior PIDS comprises two display screens: a front-mounted orange LED display showing basic bus service information, and a mid-mounted LCD screen providing additional information such as subsequent bus stops, and rail connections. Another external-facing LCD screen informs commuters about upcoming rail connections along the bus route.

USB charging ports are available at alternate seat rows with spring-loaded dust covers. USB-C charging is offered; a first for LTA buses.

The smaller interior PIDS, and the absence of rear LED PIDS displays and automatic passenger counters, mark differences from earlier LTA-procured bus models.

Finally, the rear of the bus incorporates an emergency exit hatch that can be opened from either the inside or outside. This safety feature first appeared on the Volvo BZL–SC Neustar City, and came as a result of a July 2021 bus accident that resulted in a bus flipped on its side.

Driver’s Cab

Buses procured under Contract PT601 (i.e. BYD BC12A04 and Zhongtong N12) come fitted with a Camera Mirror System in place of usual wing mirrors. Display screens located in the driver’s cab show real-time footage from high-definition cameras mounted on the exterior of the bus—where traditional wing mirrors are mounted.

The camera mirror system comprises three screens – two in place of the original wing mirrors, and a third for the bus’ left and front blind spots. Mounting points on the bus exterior allow wing mirrors to be installed if the camera system fails.

Other driver assistance features are:

• Advanced Driver Assistance System, for front and side collision warning and lane departure warning
• Anti-Fatigue system, which detects driver fatigue
• 360° surround-view camera system; generates 360° birds-eye view to aid manoeuvring using exterior cameras on all sides

Finally, the driver’s cab features standard LTA equipment – e.g. the Trapeze Common Fleet Management System (CFMS) for schedule monitoring, and the New Onboard Bus Equipment (NOBE) that controls the fare systems.

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Early Prototype

The BYD BC12A04 first appeared in a promotional video published by Zhuhai Guangtong Vehicle Manufacture Co., Ltd., a contract manufacturer of buses based in Zhuhai, China. The video, which surfaced in early 2024, was uploaded to an Alibaba listing by Zhuhai Guangtong advertising its electric buses.

The bus in the video appears to be an early production prototype. The automatic wheelchair ramp, camera mirror system, and rear emergency exit hatch, which feature on buses delivered to Singapore, are not found on this bus.

Other public buses in Singapore built by Guangtong Manufacture are the ADL Enviro500 and the ADL Enviro500 (3-door).

Video screengrabs of the interior reveal seats upholstered in blue and red, with red seats intended as priority seats. Two wheelchair bays are provided, with each wheelchair backrest fitted with a pivoting handlebar and a foldable seat.

Two wheelchair bays are provided, both located opposite the exit door. Each bay accommodates one passenger-in-wheelchair (PIW), and the wheelchair backrest contains both a foldable seat and a pivoting handlebar.

Advanced Driver Assistance Systems and an anti-fatigue system are mounted on the dashboard.

The rear section of the bus is laid out similarly to other BYD B12 buses in Singapore, including the floor step provided for passengers accessing the last row of seats (as seen from the CCTV monitor), despite being positioned at the same height as the facing seats in front.

This promotional video was removed from Alibaba sometime around September 2024.

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Weibo Post (May 2024)

In May 2024, more photos of the BYD BC12A04 were posted to Weibo by MT6735EVG.

Several modifications can be identified on the exterior of the bus when compared to the video released in early 2024, such as:

• BYD external badges, in place of Guangtong badges
• Camera side mirror systems installed; physical mirrors removed
• Escape hatch incorporated into rear window of bud
• Exterior wheelchair push buttons relocated to a lower position; with tape placed over the original position

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Other BYD B12 buses in Singapore

ComfortDelGro Bus purchased ten BYD B12A03 buses as campus shuttle buses for NUS and NTU, which commenced service in November 2022.

Another BYD B12A03 demonstrator bus (registered SG4013A) was offered to LTA for revenue service trials, commencing service in January 2024.

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Gallery (Revenue Service):

Gallery (SITCE Shuttle, November 2024)

Gallery (Pre-Delivery)

(Photos from LinkedIn by Mr Gregory Sloan, Executive Director at Challenger Bus And Coach. Guangtong Manufacture also builds buses for Challenger).

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References:

• Guangtong New 12m Electric 35 Seats Passenger City Bus 40 Seater Automatic Low Floor Public Bus Customized – Buy City Bus electric City Bus new Bus Product on Alibaba.com
• BYD has embarked on a new journey after ten years of transformation and released a new generation of pure electric commercial vehicle series (baidu.com)
• Gregory Sloan – LinkedIn Post
• Newly designed model for 2024 -… – Guangtong Vehicle Manufacture | Facebook
• Weibo Post – MT6735EVG
• New Electric Bus Features for Safer and Inclusive Journeys – Land Transport Authority

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