CTV OB Truck

Responding to the growing demand for HD broadcasts and with a fleet of already overworked outside broadcast trucks, CTV Outside Broadcast’s newest addition to its fleet, OB 9, is a fully-equipped production facility with the latest in High Definition production, mixing and recording equipment. Targeted squarely at major entertainment and sporting events throughout Europe, this 16 metre, 40 ton monster had its first outing at the recent Twenty 20 test match at Hampshire’s Rose Bowl and is already heavily booked for the remainder of the summer for several one-day cricket fixtures, before moving to the Ryder Cup Golf in September; which will be the largest HD live production to date involving 60 HD cameras.
All switching, control and monitoring of video is at HD resolution ensuring the highest possible level of picture quality and ensuring that no picture information is lost but is made available to operators and production staff. System integrator for the project, Neil Wilson: “All monitors, right down to the smallest 6” desk mounted units, are native HD resolution since it is critical that producers view the picture in its entirety without fear of missing any item on screen, no matter how small it may be.”
Mechanical considerations
OB trucks are often expected to travel thousands of miles over motorways, main roads and often culminating in tight manoeuvring over rough terrain and dirt tracks; for example to reach an isolated golf course. When it arrives it must be in one piece and operate with 100% reliability. To achieve mechanical integrity all loose items of equipment are solidly fixed and locked. Neil Wilson: “A screw and nut is not enough to hold a heavy piece of equipment in a frame. We always use Lock-Tite to ensure that once installed they will not work loose, resulting in an expensive and vital monitor or switch falling to the floor in transit. Other considerations, such as articulating arms and booms have to be considered and precautions taken to fix them in transit.”
Another unique challenge in OB vans is in the way that the sides extend, carrying walls of monitors, mixing desks and sound equipment with them. All the electrical and fibre connections between the units have to be extended and flex though up to 180. Neil Wilson:” We use U-shaped cable ladders that are fixed at one end to the main body of the truck and can move at the other, the extending side, to hold cables in position and allow them to move as the side is extended. The special consideration is in using ladders that maintain the minimum bend radius of cables, including HDSDI coax, fibre and camera triax cables. This is a critical function within the truck; the cables run through looms within the superstructure of the vehicle and cannot simply be replaced on site and the astronomical expense of some of them, particularly fibre cables means that they have to be treated with the utmost care, without limiting the functional capability of the truck.”
Installation
Building an OB truck is similar to the system integration of a full broadcast studio, with similar equipment, tools and techniques. The over-riding feature though, is the lack of space. In a studio environment space is not usually an issue; the tendency is often to allow much more than required, with the result that cable runs can be made through large cable trays and ducts simply and conveniently between equipment that is laid out and installed in racks for convenience rather than space efficiency. The converse is true in an OB van. Here equipment space is tight and items are installed with no additional access or consideration for easy installation, putting particular demands on the wiring installers. An additional constraint is working space, which is severely limited. During installation a team of ten or so installers results in severely limited operational area, with each member getting in the way of others. Looms are usually designed and manufactured on the bench before installation following a very tight design specification to ensure that the minimum amount of wiring is used so that it can be installed in the small voids under the floor and around the walls. OB vans are often built to exceedingly tight timescales which compounds the issues with everything needing to be completed at the same time.
Vision
At the front end of the chain, although physically situated at the rear of the truck, the vision area provides facilities for up to 6 operators to ‘rack’ incoming camera and other video feeds: those from external distribution systems, stump cameras, VTRs, PCs and host-provided sources. In practice the engineering team may be presented with a whole host of different camera types supplied on hire for specific events, and allowance has been made to accommodate as many as possible without needing to change input connectors or redefine channels.
Within the truck, signal routing is handled by a Probel 512 x 512 multi format Sirius Gold Video Matrix. Neil Wilson selected this device following several previously successful applications and chose it as much for its modular design which allows precise configuration as for its dual format capability, allowing rapid conversion between HD and SD operation.
Production
The largest single space within the truck is the production gallery, providing a comfortable work area for up to 10 seated production staff on two rows of desks facing a bank of high brightness LCD monitors.
The first desk carries the control panel for a Grass Valley Kalypso Duo HD/SD Production Mixer, configured in its larger 4 M/E (mix and effect) format and capable of mixing and keying up to 90 HD inputs and providing 48 auxiliary bus outputs.
Monitoring of all signals within the production gallery is achieved by a 21-screen bank of Vutrix 23” HD LCD-TFT Quad Split monitors. Each monitor handles four individual HD SDI inputs as separate channels and displays them in separate quadrants on the screen. With separate audio meters for each input, signal banners, tally blocks and the ability to display UMD text delivered to the display through an RS422 interface, the monitors perform functions that are usually achieved in two or three discrete devices. Hamish Greig comments: “Space on an OB truck is limited so any device that incorporates multiple features and delivers a significant saving in space and a useful reduction in power and heat is welcomed. These features, together with the extremely high quality and colour balance of the Vutrix screens make them an obvious choice. The minimal depth of an LCD screen compared with a CRT monitor allows us to include more equipment and operational staff in the truck as well as offering a better working environment.”
The quad split displays are also able to operate in full screen mode on one selectable input, a feature used on two of the central screens to provide preview and programme monitoring on a larger display format. Neil Wilson: “By using a common type of display we maintain consistent picture quality and viewing angle and have the flexibility to dynamically reassign monitor usage in future, should the operators prefer a different layout.” Supplementary Vutrix triple 6.4” monitors built into the desks and pole mounted 17” quad displays offer additional video monitoring for personal application on both rows of production desks.
Clive Kay, Vutrix CEO explains the philosophy behind the design of the company’s TFT range: “Our years of experience in designing SD and commercial flat screen displays combined with the massive demand for HD production and monitoring equipment naturally led us to address the market for the highest possible performance flat screen displays capable of handling HD inputs. The key design feature was to solve the TFT gamma and colorimitry variation between panels, which we do by individually grading each display and setting these parameters on a screen-by-screen basis”.
VTR
A fully fitted recording suite in the VTR area provides comprehensive facilities to record live and production feeds in the most popular digital formats in both SD and HD by means of a bank of Panasonic recorders supplemented by EVS Super SloMo units. HD recording to HD CAM is achieved using Sony HDCAM and HDSRW550s and to D5 and DVCPro using Panasonic. A second wall of 18 17” Vutrix HD LCD-TFT Quad Split monitors provides extensive monitoring of video feeds with on-screen audio meters to the crew of up to 9 engineers and support staff.
Audio
Alongside HD, audio is becoming more important as consumers expect higher quality 5.1 surround sound with their pictures. Hamish Greig “With more widespread use of home cinema systems for live TV and recorded entertainment, viewers demand superior sound quality. Our trucks are used extensively for live concert transmissions as well as recording for DVD duplication so we have invested considerable resource in ensuring top-quality sound mixing and recording in this vehicle.” To this end OB 9 carries a range of Neumann, Shure, AKG, Soundfield 5.1 surround sound mics and Sennheiser wired and wireless microphones combined with an audio matrix providing 96 x 96 analogue stereo and 128 x 128 AES channels. In total the truck has facilities to handle 128 AES inputs, 64 microphone inputs and 48 line inputs. Calrec’s Alpha digital audio console provides full EQ and dynamics on up to 20 x 5.1 surround channels, 8 x 5.1 groups and 4 x 5.1 mains.
Perhaps the single, most complicated task is in the project management of the system installation; scheduling the procurement, receipt, installation and commissioning of the myriad pieces of equipment and cabling as well as the tasks that need to be performed to power, connect and control them. Making the building of an OB van akin to that of constructing a studio complex in miniature and one a much tighter timescale.

Vutrix supplies High Definition TFT monitors for the broadcast industry and is the leading manufacturer of high-performance displays used throughout the professional TV industry in Europe and worldwide, including outside broadcast vehicles, studios and other applications where video quality and performance is paramount.