Technical Documentation

Overview

LOCK IN is a browser-based freight and trailer-loading training simulator for career and technical education. Students build trailer walls under a dispatch clock and are held to real load theory: support, bracing, staggered seams, weight balance, hazmat placed low, fragile freight protected, void elimination, and a graduated safety ladder. The simulator is free for individual players forever, and players never make an account. An instructor makes an account on the instructor dashboard, makes a crew, and gives out its join code; a free crew holds up to 9 people, and the dashboard shows each person's practice results. A license removes the limit and adds the CSV export, a signed data agreement, purchase orders and invoices, and support.

Delivery model

• No installer. No plugin, no browser extension, no app-store package, no MSI, no agent, no administrator rights.
• No on-premise component. Nothing runs on district infrastructure; no local service and no listening port on the device.
• A student opens a URL. All of the simulator's code runs client-side in the browser. Works on current Chrome, Edge, Firefox, and Safari, including Chromebooks. Designed for keyboard and mouse on classroom desktops and laptops.

Security & Privacy

• No advertising and no ad technology of any kind, anywhere on the domain. Advertising was removed permanently and is barred.
• No Google Analytics, and F-Keys adds no analytics or tracking script of its own. No tag manager, no advertising pixels, no third-party session-replay script. A reviewer can confirm this in browser developer tools. The simulator's own timed move log is described under Data Handling. Cloudflare, the content-delivery provider, sends Network Error Logging headers, which ask the browser to report failed page loads to Cloudflare.
• First-party data only. Crew records are stored in the LOCK IN database (hosted by Cloudflare in its eastern North America region). No table can be reached from a browser: every read and write goes through the LOCK IN server, which checks who is asking: an instructor must own the crew; a crew member's device must hold a valid crew token. Other users see only the public boards.
• Nothing leaves the device without a crew. A student who has not joined a crew sends no session, wall or score. A run the student chooses to sign on a public board sends three initials, the mode, that run's numbers, and the date and time, with no account or device attached. The only other data sent is a set of anonymous daily totals, such as walls finished per mode: one number per day, with no account, device, cookie or IP attached.
• Joining a crew is the consent step. The student enters the crew's code; LOCK IN shows the crew's name and sends nothing about the student yet. The student then types a name and chooses a 4-digit PIN (a PIN crew), or types the personal code the instructor issued (a manual crew, where the instructor chose the names), and LOCK IN lists what the crew will receive before the student joins. From then on the device sends the crew every wall it seals and every session that ends with CLOCK OUT, a daily submit or the end of the shift, and the instructor sees them on the dashboard. LEAVE THE CREW ON THIS DEVICE stops it at once. PINs are stored only as salted PBKDF2-SHA256 hashes and device tokens only as SHA-256 hashes; five wrong PINs lock a name for 15 minutes, and the instructor can reset a PIN or issue a new personal code.
• All simulator data goes to the LOCK IN database over HTTPS/TLS (TCP 443, outbound). No inbound connections to the device.
• Notice of unauthorized access. If F-Keys confirms that saved data was accessed without permission, it tells each affected school, program and employer with an agreement as soon as it confirms it and within 72 hours, and posts a notice in the simulator.

Data Handling

What is collected

• No student account, email, phone, home address or date of birth, and no payment data from students. A name exists only on a crew: the one the student types for a PIN crew, or the one the instructor types for a manual crew. First names or pseudonyms work.
• For a crew member: the name, a salted PBKDF2-SHA256 hash of the PIN (PIN crews) or the instructor-issued personal code (manual crews), a SHA-256 hash of each device's crew token, when the student joined and last played, and every wall and session the device sent while on the crew: score, load integrity, density, pace, safety incidents with the rule broken, collapses, water breaks, rotations, lifts, a timed log of moves (up to 6,000 per session, at 0.1 s), session start and end times, and the app version.
• For an instructor: an email address and a password (stored only as a salted PBKDF2-SHA256 hash), when the account was made and when it last signed in, and the crews the instructor makes with their names and personal codes.

Where it lives and who touches it

• Subprocessors for the product, complete list: Cloudflare (the LOCK IN server and database, eastern North America region; it stores all crew data; also content delivery and security for the website), GitHub (GitHub Pages, website hosting), and Resend, the email service that sends instructor account emails (it receives the instructor's email address and the message). F-Keys uses no others. Each provider uses its own subprocessors. The mail provider (for email sent to F-Keys) and the payment processor (for facility card payments) are not part of the product and receive no data from it.
• Who sees a student's results: only the instructor of the crew the student joined, on the dashboard. No other student, crew or instructor can. A licensed crew's instructor can export its walls and sessions as CSV at any time.
• Return and deletion on termination are addressed in the data privacy agreement (below).
• Retention and deletion: a crew member's records stay until the instructor removes the student or deletes the crew (either deletes them at once), until the instructor's account is deleted, or until F-Keys deletes them on a confirmed request, within 30 days. An instructor account with no sign-in for 24 months is deleted with its crews, except while it runs a licensed crew. When a school's or program's agreement with F-Keys ends, F-Keys deletes the student records it covers within 60 days, unless the agreement says otherwise. Send requests to privacy@trailer-load.com. A CSV a crew exported is outside LOCK IN, and deleting with F-Keys does not delete it.
• Public boards: the daily and TRAILER-LOAD boards show three self-chosen initials and the score; the public board data also carries that run's integrity and date. No board shows a name, and nothing links a signature to a student.
• Earlier versions: LOCK IN 3 had player accounts with usernames. When LOCK IN 4.0 shipped, F-Keys deleted every one of them with everything saved to them.

Accessibility

Implemented and shipping today: keyboard play for every menu and mode (Tab and Enter in the menus; arrows move, [ and ] choose a piece, Enter or Space places, R rotates, P or Escape pauses; one-key shortcuts can be turned off in Settings), colorblind modes, a reduced-motion mode, text scaling, and high-contrast outlined text for readability during a wall. This page describes what is built rather than claim a formal conformance level: LOCK IN has not undergone a third-party WCAG audit and F-Keys does not assert a WCAG or Section 508 conformance level. If your institution requires a formal accessibility representation as a condition of award, contact F-Keys to discuss scope.

Content & Age Suitability

• Workplace-safety and logistics themed. No violence, no graphic content.
• No student-to-student chat and no free-text messaging between users. The only user-authored text visible to others is three initials on a board, and a crew name, shown to anyone who enters that crew's join code. Initials are three letters A to Z, and the server refuses a list of offensive combinations. A crew member's name is visible only to that crew's instructor. Crew names (free text up to 48 characters) are not run through a word filter; report one to privacy@trailer-load.com and F-Keys will remove it.
• Designed for students approximately 14 and older. LOCK IN is not directed to children under 13. A student under 13 can play without a crew, which sends nothing personal, and should join only a crew a school or program set up with the consent the law requires.

Document Library

Informational documents are available to read and print now. Contract instruments are prepared per institution and provided on request so your counsel reviews the version you will actually sign.

How to Buy

Pricing is published on the programs page. A site license is $1,950 for 12 months from a start date you choose, for one campus, unlimited students, deliberately set under common single-signature and micro-purchase thresholds. Three routes:

• Purchase order. F-Keys registers in your vendor system, provides a W-9, and invoices against your PO, net-30.
• Perkins-funded requisition. The Program & Funding Overview maps the purchase to allowable local uses of Perkins V funds to assist your own determination.
• Student course fee. A $29 per-student, per-semester option that runs through your course-fee or bookstore system and needs no procurement.

If your award requires insurance, send the required limits with your quote request.

Contact

• Sales, quotes, documentation: vince@trailer-load.com
• Data protection / privacy: privacy@trailer-load.com
• Try it now: trailer-load.com/lock-in.html. No account is needed to play.