Inside the Archive #62: Traineeships in the archive

Thom Walker is one of the BFI National Archive trainees, developing their craft in the Archive Technology team at the BFI National Archive Conservation Centre in Berkhamsted.

This 18-month trainee programme is a critical part of our plans to develop the future workforce for screen heritage in the UK, opening pathways into entry-level roles. This programme is funded by the Heritage Innovation Lottery Fund. Today, we’re shining a light on the work Thom has been doing as part of his traineeship.

– Nicky Williams, Head of Heritage Programmes

“Standing by to roll VT” – these are words that are common parlance on any live broadcast or event. These days, they mean ‘I’m ready and waiting to press whichever key on my keyboard this software demands’. Not long ago it was a slightly more involved process of playing back a new and healthy tape. However, in the the case of digitising the troublesome ageing MII tapes (a videocassette format) from the TV-am collection, the process isn’t so simple.

As a part of my training with the BFI National Archive Technology (ATG) team, Charles Fairall has been demonstrating the challenges and pitfalls faced when getting difficult videotapes ready to roll.

My own experience with videotape is limited to a vague childhood recollection of rewatching a VHS of The Aristocats (1970) every time I visited my grandparents, to the point of watching it in rewind just to change it up a little. As such, the three weeks of training thus far have been something of a crash course in videotape technology. We’ve covered everything from how to safely handle delicate magnetic tapes to alternating current (AC) theory and how the PAL (Phase Alternating Line) format is encoded. Quite the odyssey for just three weeks.

In order to play a videotape, you need two things: one videotape and one videotape recorder (VTR). Easy… however, if either of these are imperfect, the results can be catastrophic. Any misalignment of the VTR can mangle your tapes, causing the irretrievable loss of the one-of-a-kind master materials we have been given to protect and preserve. A bad tape can also destroy itself, causing major damage to the VTR, reducing the lifespan of the machine by thousands of hours of footage. Fewer working players means fewer digitised tapes.

Mould is a common issue for tapes. For some formats, this mould can simply be cleaned off. With MII, for whatever reason – potentially due to the material composition of the binders – this mould shows signs of having eaten away at the tape and caused a fusing of substrate. If a tape with this issue is played, this small fusing causes the extremely thin tape to tear across its weak vertical plane, destroying it and its contents entirely.

We begin by heat-treating the cassette. This helps to rebind the tape, lessening the effect of shedding – a common issue for tapes in which the surfaces deteriorate and come away (see the final ‘Anatomy of Videotape’ video for the brilliant research explaining/demonstrating this process). Once the tape has reacclimatised, we open up the cassette to visually inspect what little of the tape is visible, looking for tiny white specks or patches that are signs of mould. We remove the tape from the cassette, note any visible deformation and very gently wind the reel – too much resistance on the tape indicates serious issues. If the tape appears healthy, we will put the tape into a modified VHS cleaner. The tape runs across a burnishing post and a slow-turning lint-free fabric; the combination of the two attempts to remove shedding clumps and foreign substances from the tape. This is a delicate process which is closely observed, as it rapidly highlights the extent to which the tape is damaged. After numerous passes the tape is ready for an excursion into the VTR.

But how do we make the VTR ready for the tape? For brevity, we’ll skip over the extensive work Charles, Andy and the ATG team do to check the health of the densely packed printed circuit board (PCB), ensure the precision mechanical parts are moving well, and make any tiny adjustments required to get the minuscule head-gap perfectly aligned. Let’s assume all that has been completed. Firstly, the tape path must be cleaned. Every guide, pinch roller, capstan and head unit must be wiped very gently to remove any buildup. Then we check the player against a reference tape. After that, the colour bars and test tones at the start of the tape allow us to set levels accurately to match the recording. At this point, with some trepidation and under a very watchful eye, we’re ready to roll VT.

This project has highlighted the immediacy of the issues around digitising videotapes, especially ones that haven’t been stored in prime conditions. With the tapes deteriorating by the day and required equipment becoming ever more scarce, it feels like a pertinent time to ask what the future of tape digitisation looks like. There are immediate things we can do, like continuing to share knowledge of best practice from those with experience in the subject. We’re designing an extra-gentle cleaner informed by the issues we’re observing, for which we hope to utilise open-source image recognition software to help us evaluate and gather information on the tapes, which could be invaluable for future research.

However, the largest, most meaningful leaps in videotape media preservation will undoubtedly come from furthering our understanding of magnetic media through continued scientific research. Precious little is known about the subtle material differences between formats, despite being the carrier for so much of our TV heritage. Charles has been coordinating research for some time in order to understand how best to extend the life of high-risk tapes, and there’s even ongoing research into how to retrieve media from tapes that are too far gone to survive a VTR. With the exciting introduction of the heritage science lab – first explored in our earlier Inside the Archive blog about the new moving image conservation research laboratory – it feels like a vital moment to be asking some urgent questions about how research can help us best preserve this material.

– Thom Walker, Trainee Archive Technology Technician and Charles Fairall, Videotape and Engineering Advisor

The Inside the Archive blog is supported by the BFI Screen Heritage Fund, awarding National Lottery funding.