It’s 5pm on a sunny Friday in Crawley and I’ve walked into the cell block to be booked in for the next 17 hours. I’m asked to stand in front of the desk and the Sergeant goes through my personal details, questions me about any medical issues, then takes my phone and keys for safe keeping. He gives me a leaflet which I save to read later.

Next to me is a male shouting and swearing, with four officers trying to calm him down. He isn’t happy, as he says he was only released yesterday morning and now he’s back. It’s an unsettling start to my time here, but one of the officers is a screen between us so I feel safe.

The Sergeant tells me as I’m low risk I will have a welfare check once an hour, then leads me down to my cell. For now I seem to be the only one in detention. There are tissues by the toilet, a blue mattress and a pillow. I think the Sergeant tries to shut the door gently but it still makes that noise you hear on TV; a cell door closing followed by the handle being turned to lock it.

I decide to read the leaflet about an initiative to support women in the early stages of the Criminal Justice system. All females are offered a referral to the scheme. On the leaflet there’s a picture of a butterfly with the words “Just when the caterpillar thought the world was over….she became a butterfly”. Love that!

So this is it – my cell for the next 17 hours. I go to look at my watch but I had to leave it at the desk. I sit on the thin blue mattress which is about 2 inches deep including the blue plastic cover. Sitting on it, the mattress goes much thinner so I can feel the hard bench underneath. Within 10 minutes my bottom has gone numb and I find myself walking around the cell to get the circulation going again.

There is silence, no neighbours; the only sound a dull buzzing noise in the cell which I presume is from the heating unit in the ceiling. I’ve just had my first welfare check and when I ask the time I’m told it‘s 6:30pm. Asking the time is to become a feature of my welfare checks.

I also ask for some water which is brought to me. I start sipping it like it’s rationed. I drink a lot of water and am already finding it frustrating that I can’t just go and get some. I suppose I could use the buzzer – but I don’t want them to think I’m going to be a pain!

Time goes by slowly and it starts getting busier. The cells either side now have people in and thankfully they’re quiet like me. I’m guessing the others are thinking about why they’re here, when they’ll be interviewed, what will happen. I find myself talking out loud and – when it echoes around the cell – my thoughts turn to my children as they love an echo.

The hatch opens and I’m asked if I’d like anything to eat. I ask for pasta and some more water. A short while later the hatch opens again and I’m handed a microwaved pasta bolognaise and two cups of water. The food’s hot and tasty, with lots of veg, and I find it perfectly acceptable. I hear my neighbour ask for more rice and very soon they come back and say “here you go, some more rice”.

One issue making me anxious is the toilet: it’s a stainless steel plain loo, above it is a small inverted sink that cold water comes out of (not drinking water). The toilet area is pixelated on the CCTV but I’m concerned that someone could look through the peephole or open the hatch. So I come up with a plan to wait until my next welfare check, then use the loo as soon as they close the hatch.

I start guessing the time as it seems ages since my last check at 7:30pm. When the hatch opens and I ask the time, it’s 9:45pm. I ask for a hot chocolate and then my lights out. I lie down and pull the safety blanket over me, I also have a normal white blanket and I wrap this around the blue plastic pillow to make it slightly softer.

It starts to get noisy – exactly what I’d expect for a Friday night in Crawley. Now It’s 00.30am and I haven’t been able to sleep so ask for another hot drink. The temperature has dropped slightly and it’s not as warm as it was.

It’s 2am – and I just dozed off, but only for minutes as I’m woken by a welfare check at the hatch. I don’t reply, so the words “Sarah, are you ok?” echo around the cell and I sit up slightly disorientated and mumble a reply. But that’s that – no more dozing, I sit up.

I have a visit from the Custody Sergeant around 2.30am. He opens the door and we speak about the ICV Scheme; he compliments the Crawley Panel which is good to hear even in the middle of the night! He gets me another hot chocolate and says he has to go as there’s a drunk female coming in from Horsham.

The drunk female arrives a short time later and for the next three hours kicks her cell door constantly, shouting at anyone who tells her to be quiet.

Welfare checks continue through the night. I get used to hearing the footsteps approach and, rather than talk each time the hatch opens, I raise my hand in an “I’m ok” kind of way.

I lie on the bench and listen to the hustle of the suite, people coming in, searches in cells, the uncooperative, the cooperative, staff checking on people answering buzzers, phone calls from solicitors. It’s a constant hive of activity.

At 6.15am my cell door opens. They’ve come to clean the cell, take my empty cups and the leaflet I’d managed to turn into a fan and then a finger puzzle. I have to pass on breakfast as I can’t eat beans, so just a cup of tea it is.

I leave slightly earlier than planned as I have an hour to travel home – so in the end I had 15 hours in Custody.

People ask me why I did this. It’s purely to try and get a small understanding of the isolation someone may feel being locked in a cell, and to see if there’s anything I can suggest to improve the experience. Without doubt it was worthwhile.

I’m keen to look into the possibility of having drinking water in the cells, as this would not only help the detainee but save on staff time going to and from the kitchen.

I plan to investigate if there’s a national standard for mattresses in cells. The length of the bench was fine – I’m 6 foot tall and could lie straight. I was happy with the temperature and cleanliness of the cells; when I asked for a toothbrush I got one, and my neighbours got the extra food they asked for.

More than ever I stand by the change I would like to see to female hygiene in custody; it’s not a pleasant experience using the toilet in a cell anyway, but to make a female who is menstruating have to buzz every time she needs certain products just isn’t right in my opinion. Sussex now offer a good variety of products but I still feel there’s work to be done in this area.

Would I do it again? Yes, without a doubt, if it was to improve the welfare and conditions for the detainees.